Single snapshot for multiple applications

ABSTRACT

An information management system according to certain aspects may be configured to generate a snapshot of data relating to a plurality of applications. The system may include a plurality of data agents, wherein each data agent is associated with at least one of a plurality of applications, and data generated by the plurality of applications is stored in a logical volume in primary storage. The system may also include a snapshot manager configured to detect the plurality of applications; check with the plurality of data agents whether the associated applications are in consistent states; obtain a snapshot of the logical volume in response to receiving notifications from the plurality of data agents that the associated applications are in consistent states; and generate mapping information between a particular one of the plurality of applications and a portion of the snapshot relating to the particular one of the plurality of applications.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/163,465, filed Jan. 24, 2014, and entitled “SINGLE SNAPSHOT FORMULTIPLE APPLICATIONS”. Any and all applications, if any, for which aforeign or domestic priority claim is identified in the Application DataSheet of the present application are hereby incorporated by reference intheir entireties under 37 CFR 1.57.

BACKGROUND

Businesses worldwide recognize the commercial value of their data andseek reliable, cost-effective ways to protect the information stored ontheir computer networks while minimizing impact on productivity.Protecting information is often part of a routine process that isperformed within an organization.

A company might back up critical computing systems such as databases,file servers, web servers, and so on as part of a daily, weekly, ormonthly maintenance schedule. The company may similarly protectcomputing systems used by each of its employees, such as those used byan accounting department, marketing department, engineering department,and so forth.

Given the rapidly expanding volume of data under management, companiesalso continue to seek innovative techniques for managing data growth, inaddition to protecting data. For instance, companies often implementmigration techniques for moving data to lower cost storage over time anddata reduction techniques for reducing redundant data, pruning lowerpriority data, etc.

Enterprises also increasingly view their stored data as a valuableasset. Along these lines, customers are looking for solutions that notonly protect and manage, but also leverage their data. For instance,solutions providing data analysis capabilities, information management,improved data presentation and access features, and the like, are inincreasing demand.

Snapshots can provide point-in-time copies of production data that canbe restored for reference at a future time. In certain systems, a singlelogical volume of data (e.g., logical unit number (LUN)) may have datastored therein associated with a plurality of different applicationsand/or agents. Snapshots are often taken of an entire logical volumeeven when only one of the associated applications is requesting thesnapshot.

SUMMARY

Data associated with multiple applications may be stored on the samelogical volume (e.g., LUN). In general, when an application requests asnapshot of data associated with the application, the snapshot of theentire volume is taken, although the data of interest may only be thedata associated with the requesting application. If a snapshot is takenof the entire volume in order to accommodate a request of oneapplication, or a subset of applications associated with the volume, thesnapshot data not associated with the requesting application may beunused, thereby creating system inefficiency.

In order to address these and other challenges, an informationmanagement system is provided to implement a combined single snapshot ofdata associated with multiple applications, according to certain aspectsof the disclosure. For example, the information management system cancoordinate snapshot operations such that a single snapshot can be takenfor multiple applications, wherein the data associated with the multipleapplications is residing on the same volume. For instance, theinformation management system can take a single snapshot of dataassociated with applications that have a similar snapshot frequency. Theapplications associated with the data stored on a particular volume caneach be quiesced or placed in a consistent state, and the informationmanagement system can take a single snapshot of the volume, instead oftaking different snapshots of the volume for each of the applications.The information management can create metadata (e.g., index) relating towhich portion of the snapshot is associated with which application. Thesingle snapshot can be stored in one or more secondary storage devices.When data associated with an application is to be restored from thestored single snapshot, the information management system can refer tothe metadata to locate the data associated with the application.

In this manner, the information management system can reduce the numberof snapshots obtained for various applications. By utilizing a combinedsingle snapshot for multiple applications, the information managementsystem reduces the number of snapshots taken since a snapshot of avolume can be taken less frequently. This can reduce the amount ofresources used for generating and storing snapshots. In some cases, theorganization associated with the information management system licensesthe snapshot technology and may be allowed a limited number ofsnapshots. For example, a license for a snapshot software may be pricedbased on the number of allowed snapshots. Accordingly, taking fewersnapshots to back up data in the primary storage can be economical.

An information management system according to certain aspects may checkor determine whether snapshot operations will work prior to executingthem. The information management system may check various factors orparameters relating to a snapshot storage policy to verify whether thestorage policy will work at runtime. The information management systemmay also check whether a particular system configuration is supported inconnection with snapshot operations. The result of the determination canbe provided in the form of a “snapshot readiness report,” which maysummarize any problems found with the snapshot storage policy. Thesnapshot readiness report may provide recommended course of action orsolutions for resolving any identified issues. The snapshot readinessreport may be used in connection with any system capable of performingsnapshot operations, including systems that implement single snapshotfor multiple applications.

According to certain embodiments, an information management systemconfigured to generate a snapshot of data associated with a plurality ofapplications is provided. The system can include a plurality of dataagents executing at least in part on a client computing device. Eachdata agent may be associated with at least one of a plurality ofapplications executing on the client computing device. Data generated bythe plurality of applications may be stored in a logical volume inprimary storage. The system may also include computer hardware. Thesystem can also include a snapshot manager executing on the computerhardware. The snapshot manager may be configured to detect the pluralityof applications executing on the client computing device. The snapshotmanager may also be configured to check with the plurality of dataagents whether the associated applications are in consistent states. Thesnapshot manager can be further configured to, in response to receivingnotifications from the plurality of data agents that the associatedapplications are in consistent states, obtain a snapshot of the logicalvolume. The snapshot manager may additionally be configured to generatemapping information between a particular one of the plurality ofapplications and a portion of the snapshot relating to the particularone of the plurality of applications. The snapshot manager can also beconfigured to store the snapshot in secondary storage.

According to some embodiments, a method of generating a snapshot of datarelating to a plurality of applications is provided. The method caninclude detecting, using computer hardware, a plurality of applicationsexecuting on a client computing device, a plurality of data agentsexecuting at least in part on the client computing device, each dataagent being associated with at least one of the plurality ofapplications executing on the client computing device, data generated bythe plurality of applications being stored in a logical volume inprimary storage. The method may also include sending requests to theplurality of data agents to check whether the associated applicationsare in consistent states. The method can further include, in response toreceiving notifications from the plurality of data agents that theassociated applications are in consistent states, obtaining a snapshotof the logical volume. The method may further include generating, usingthe computer hardware, mapping information between a particular one ofthe plurality of applications and a portion of the snapshot relating tothe particular one of the plurality of applications. The method canadditionally include storing the snapshot in secondary storage.

According to other embodiments, an information management systemconfigured to generate a snapshot of data relating to a plurality ofapplications is provided. The system can include a first data agentexecuting at least in part on a client computing device, the first dataagent being associated with a first application executing on the clientcomputing device. The system can also include a second data agentexecuting at least in part on the client computing device, the seconddata agent being associated with a second application executing on theclient computing device, data generated by the first application anddata generated by the second application being stored in a logicalvolume in primary storage. The system may also include a snapshotmanager executing on computer hardware. The snapshot manager may beconfigured to communicate with the first data agent to check whether thefirst application is in a consistent state and communicate with thesecond data agent to check whether the second application is in aconsistent state. The snapshot manager may also be configured to, inresponse to receiving a first notification from the first data agentthat the first application is in a consistent state and a secondnotification from the second data agent that the second application isin a consistent state: obtain a snapshot of the logical volume; copy thesnapshot of the logical volume to secondary storage using one or moremedia agents; generate first mapping information between the firstapplication and a portion of the snapshot relating to the firstapplication based at least in part on metadata relating to a firstlocation of the data generated by the first application in the logicalvolume, the metadata relating to the first location obtained by thefirst data agent; and generate second mapping information between thesecond application and a portion of the snapshot relating to the secondapplication based at least in part on metadata relating to a secondlocation of the data generated by the second application in the logicalvolume, the metadata relating to the second location obtained by thesecond data agent.

According to certain embodiments, a method of generating a snapshot ofdata relating to a plurality of applications is provided. The method mayinclude communicating with a first data agent to check whether a firstapplication is in a consistent state, the first data agent executing atleast in part on a client computing device, the first applicationexecuting on the client computing device, the first data agent beingassociated with the first application. The method may also includecommunicating with a second data agent to check whether a secondapplication is in a consistent state, the second data agent executing atleast in part on the client computing device, the second applicationexecuting on the client computing device, the second data agent beingassociated with the second application, data generated by the firstapplication and data generated by the second application being stored ina logical volume in primary storage. The method can also include, inresponse to receiving a first notification from the first data agentthat the first application is in a consistent state and a secondnotification from the second data agent that the second application isin a consistent state, obtaining a snapshot of the logical volume usingcomputer hardware. The method can further include copying the snapshotof the logical volume to secondary storage using one or more mediaagents. The method may further include generating first mappinginformation between the first application and a portion of the snapshotrelating to the first application based at least in part on metadatarelating to a first location of the data generated by the firstapplication in the logical volume, the metadata relating to the firstlocation obtained by the first data agent. The method may additionallyinclude generating second mapping information between the secondapplication and a portion of the snapshot relating to the secondapplication based at least in part on metadata relating to a secondlocation of the data generated by the second application in the logicalvolume, the metadata relating to the second location obtained by thesecond data agent.

According to some embodiments, an information management systemconfigured to generate a snapshot of data relating to a plurality ofapplications is provided. The system can include a plurality of dataagents executing at least in part on a client computing device, eachdata agent being associated with at least one of a plurality ofapplications executing on the client computing device, wherein: datagenerated by the plurality of applications is stored in a logical volumein primary storage; and the plurality of data agents comprises at leasta database data agent associated with a database application, thedatabase data agent configured to back up one or more log files of adatabase log of the database application separately from data of thedatabase application. The system may also include a snapshot managerexecuting on computer hardware. The snapshot manager may be configuredto detect the plurality of applications executing on the clientcomputing device. The snapshot manager may also be configured to, inresponse to receiving notifications from the plurality of data agentsthat the associated applications are in consistent states, obtain asnapshot of the logical volume that comprises the data generated by theplurality of applications. The snapshot manager can also be configuredto generate mapping information between a particular one of theplurality of applications and a portion of the snapshot relating to theparticular one of the plurality of applications, the mapping informationcomprising database application mapping information between the databaseapplication and a portion of the snapshot relating to the databaseapplication. The snapshot manager can further be configured to copy thesnapshot to the secondary storage using one or more media agents. Thesnapshot manager can additionally be configured to truncate the databaselog of the database application.

According to other embodiments, a method of generating a snapshot ofdata relating to a plurality of applications is provided. The method caninclude detecting a plurality of applications executing on a clientcomputing device, a plurality of data agents executing at least in parton the client computing device, each data agent being associated with atleast one of the plurality of applications executing on the clientcomputing device, wherein: data generated by the plurality ofapplications is stored in a logical volume in primary storage; and theplurality of data agents comprises at least a database data agentassociated with a database application, the database data agentconfigured to back up one or more log files of a database log of thedatabase application to secondary storage separately from data of thedatabase application. The method may also include sending requests tothe plurality of data agents to check whether the associatedapplications are in consistent states. The method may further include,in response to receiving notifications from the plurality of data agentsthat the associated applications are in consistent states, obtaining asnapshot of the logical volume that comprises the data generated by theplurality of applications. The method can further include generatingmapping information between a particular one of the plurality ofapplications and a portion of the snapshot relating to the particularone of the plurality of applications, the mapping information comprisingdatabase application mapping information between the databaseapplication and a portion of the snapshot relating to the databaseapplication. The method can additionally include copying the snapshot tothe secondary storage using one or more media agents. The method mayalso include truncating the database log of the database applicationusing computer hardware.

According to certain embodiments, an information management systemconfigured to restore data of an application from a snapshot comprisingdata of a plurality of applications is provided. The system can includecomputer hardware and a snapshot manager executing on the computerhardware. The snapshot manager may be configured to receive instructionsto restore data of a first application from a snapshot in secondarystorage, the snapshot comprising data of a plurality of applicationsstored in a logical volume in primary storage at a first time, theplurality of applications comprising the first application and executingon a client computing device at the first time, the plurality ofapplications being in consistent states at the first time. The snapshotmanager may also be configured to access mapping information that mapsdata of the first application in the snapshot to the first application.The snapshot manager may be further configured to locate a portion ofthe snapshot corresponding to the data of the first application to berestored. The snapshot manager may additionally be configured to copythe portion of the snapshot from the secondary storage to a primarystorage device using one or more media agents.

According to some embodiments, a method of restoring data of anapplication from a snapshot comprising data of a plurality ofapplications is provided. The method can include receiving instructionsto restore data of a first application from a snapshot in secondarystorage, the snapshot comprising data of a plurality of applicationsstored in a logical volume in primary storage at a first time, theplurality of applications comprising the first application and executingon a client computing device at the first time, the plurality ofapplications being in consistent states at the first time. The methodmay also include accessing mapping information that maps data of thefirst application in the snapshot to the first application. The methodmay further include locating, using computer hardware, a portion of thesnapshot corresponding to the data of the first application to berestored. The method can also include copying the portion of thesnapshot from the secondary storage to a primary storage device usingone or more media agents.

According to other embodiments, an information management systemconfigured to generate snapshots is provided. The system may include astorage manager, executing on computer hardware, configured to initiategeneration of a snapshot of data in primary storage. The system may alsoinclude one or more media agents, executing on computer hardware,configured to obtain a snapshot of data in the primary storage and incommunication with secondary storage for storing the snapshot. Thesystem can also include a snapshot readiness manager executing oncomputer hardware. The snapshot readiness manager may be configured toaccess at a first time a storage policy defining criteria associatedwith a snapshot operation to obtain a snapshot of data in the primarystorage, the storage policy configured to instruct the storage managerto initiate the snapshot operation, and the storage manager configuredto instruct the one or more media agents to obtain the snapshot for thesnapshot operation. The snapshot readiness manager may also beconfigured to determine without executing the storage policy whetherexecution of the storage policy will succeed at a second time that islater than the first time. The snapshot readiness manager may be furtherconfigured to provide a result from the determination as to whether theexecution of the storage policy will succeed.

According to certain embodiments, a method of verifying snapshot storageoperations for an information management system is provided. The methodmay include accessing at a first time, using computer hardware, astorage policy defining criteria associated with a snapshot operationfor obtaining a snapshot of data in primary storage of an informationmanagement system. The information management system may include astorage manager executing on computer hardware and configured toinitiate generation of a snapshot of data stored in the primary storage.The information management system may also include one or more mediaagents executing on computer hardware and configured to obtain asnapshot of data stored in the primary storage. The storage policy maybe configured to instruct the storage manager to initiate the snapshotoperation. The storage manager may be configured to instruct the one ormore media agents to obtain the snapshot for the snapshot operation. Themethod can also include determining whether execution of the snapshotstorage policy will succeed at a second time that is later than thefirst time, said determining being performed without executing thesnapshot storage policy. The method may further include providing aresult from said determining whether execution of the snapshot storagepolicy will succeed.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary informationmanagement system.

FIG. 1B is a detailed view of a primary storage device, a secondarystorage device, and some examples of primary data and secondary copydata.

FIG. 1C is a block diagram of an exemplary information management systemincluding a storage manager, one or more data agents, and one or moremedia agents.

FIG. 1D is a block diagram illustrating a scalable informationmanagement system.

FIG. 1E illustrates certain secondary copy operations according to anexemplary storage policy.

FIGS. 1F-1H are block diagrams illustrating suitable data structuresthat may be employed by the information management system.

FIG. 2 illustrates an example information management system for snapshotmanagement according to one or more embodiments disclosed herein.

FIG. 3 illustrates an example data storage device comprising one or morevolumes of client production data in accordance with one or moreembodiments disclosed herein.

FIG. 4 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary information management systemconfigured to implement single snapshot for multiple applications,according to certain embodiments.

FIG. 5 is a data flow diagram illustrative of the interaction betweenthe various components of another exemplary information managementsystem configured to implement recovery operations from a singlesnapshot for multiple applications, according to certain embodiments.

FIG. 6 is a flow diagram illustrative of one embodiment of a routine forcreating a single snapshot for multiple applications.

FIG. 7 is a flow diagram illustrative of one embodiment of a routine forrestoring data of an application from a single snapshot for multipleapplications.

FIG. 8 provides a flowchart illustrating a process for generating sharedsnapshots in accordance with one or more embodiments disclosed herein.

FIG. 9 provides a flowchart illustrating a process for grouping snapshotrequests according to one or more embodiments disclosed herein.

FIG. 10 provides a flowchart illustrating a process for restoring from ashared snapshot according to one or more embodiments disclosed herein.

FIG. 11 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary information management systemconfigured to implement snapshot readiness determination, according tocertain embodiments.

FIG. 12 is a flow diagram illustrative of one embodiment of a routinefor determining snapshot readiness.

DETAILED DESCRIPTION

Systems and methods are described herein for implementing singlesnapshot for multiple applications and for checking and reporting onsnapshot readiness. Examples of such systems and methods are discussedin further detail herein, e.g., with respect to FIGS. 2-12. Moreover, itwill be appreciated that single snapshot for multiple applications andsnapshot readiness checking and reporting may be implemented byinformation management systems such as those that will now be describedwith respect to FIGS. 1A-1H. And, as will be described, the componentryfor implementing single snapshot for multiple applications and snapshotreadiness checking and reporting can be incorporated into such systems.

System Overview

The systems and methods described with respect to FIGS. 1A-1H can beused for implementing single snapshot for multiple applications. In someembodiments, a snapshot manager is a software module that forms a partof or resides on the storage manager 140 or, alternatively, the mediaagents 144. The snapshot manager can additionally be a software moduleexecuting on one or more of the client computing devices 102. In someembodiments, the snapshot manager may be implemented as a part of thedata agent 142. Single snapshot for multiple applications will bediscussed in more detail with respect to FIGS. 2-10. Furthermore,systems and methods for checking and reporting on snapshot readiness arealso described herein, with particular respect to FIGS. 11-12. In someembodiments, a snapshot readiness manager is a software module thatforms a part of or resides on the storage manager 140 or, alternatively,the media agents 144. The snapshot readiness manager can additionally bea software module executing on one or more of the client computingdevices 102. In certain embodiments, the snapshot readiness manager maybe implemented as a part of the data agent 142. In some embodiments, thesnapshot manager and the snapshot readiness manager described herein areimplemented as separate modules; in other embodiments, they areimplemented as a single unified module that executes on one or more ofthe above-mentioned components.

Information Management System Overview

With the increasing importance of protecting and leveraging data,organizations simply cannot afford to take the risk of losing criticaldata. Moreover, runaway data growth and other modern realities makeprotecting and managing data an increasingly difficult task. There istherefore a need for efficient, powerful, and user-friendly solutionsfor protecting and managing data.

Depending on the size of the organization, there are typically many dataproduction sources which are under the purview of tens, hundreds, oreven thousands of employees or other individuals. In the past,individual employees were sometimes responsible for managing andprotecting their data. A patchwork of hardware and software pointsolutions has been applied in other cases. These solutions were oftenprovided by different vendors and had limited or no interoperability.

Certain embodiments described herein provide systems and methods capableof addressing these and other shortcomings of prior approaches byimplementing unified, organization-wide information management. FIG. 1Ashows one such information management system 100, which generallyincludes combinations of hardware and software configured to protect andmanage data and metadata generated and used by the various computingdevices in the information management system 100.

The organization which employs the information management system 100 maybe a corporation or other business entity, non-profit organization,educational institution, household, governmental agency, or the like.

Generally, the systems and associated components described herein may becompatible with and/or provide some or all of the functionality of thesystems and corresponding components described in one or more of thefollowing U.S. patents and patent application publications assigned toCommVault Systems, Inc., each of which is hereby incorporated in itsentirety by reference herein:

-   -   U.S. Pat. No. 8,285,681, entitled “Data Object Store and Server        for a Cloud Storage Environment, Including Data Deduplication        and Data Management Across Multiple Cloud Storage Sites”;    -   U.S. Pat. No. 8,307,177, entitled “Systems And Methods For        Management Of Virtualization Data”;    -   U.S. Pat. No. 7,035,880, entitled “Modular Backup and Retrieval        System Used in Conjunction With a Storage Area Network”;    -   U.S. Pat. No. 7,343,453, entitled “Hierarchical Systems and        Methods for Providing a Unified View of Storage Information”;    -   U.S. Pat. No. 7,395,282, entitled “Hierarchical Backup and        Retrieval System”;    -   U.S. Pat. No. 7,246,207, entitled “System and Method for        Dynamically Performing Storage Operations in a Computer        Network”;    -   U.S. Pat. No. 7,747,579, entitled “Metabase for Facilitating        Data Classification”;    -   U.S. Pat. No. 8,229,954, entitled “Managing Copies of Data”;    -   U.S. Pat. No. 7,617,262, entitled “System and Methods for        Monitoring Application Data in a Data Replication System”;    -   U.S. Pat. No. 7,529,782, entitled “System and Methods for        Performing a Snapshot and for Restoring Data”;    -   U.S. Pat. No. 8,230,195, entitled “System And Method For        Performing Auxiliary Storage Operations”;    -   U.S. Pat. No. 7,315,923, entitled “System And Method For        Combining Data Streams In Pipelined Storage Operations In A        Storage Network”;    -   U.S. Pat. No. 8,364,652, entitled “Content-Aligned, Block-Based        Deduplication”;    -   U.S. Pat. Pub. No. 2006/0224846, entitled “System and Method to        Support Single Instance Storage Operations”;    -   U.S. Pat. No. 8,578,120, entitled “Block-Level Single        Instancing”;    -   U.S. Pat. Pub. No. 2009/0319534, entitled “Application-Aware and        Remote Single Instance Data Management”;    -   U.S. Pat. Pub. No. 2012/0150826, entitled “Distributed        Deduplicated Storage System”;    -   U.S. Pat. Pub. No. 2012/0150818, entitled “Client-Side        Repository in a Networked Deduplicated Storage System”;    -   U.S. Pat. No. 8,170,995, entitled “Method and System for Offline        Indexing of Content and Classifying Stored Data”;    -   U.S. Pat. No. 7,107,298, entitled “System And Method For        Archiving Objects In An Information Store”;    -   U.S. Pat. No. 8,230,195, entitled “System And Method For        Performing Auxiliary Storage Operations”;    -   U.S. Pat. No. 8,229,954, entitled “Managing Copies Of Data”; and    -   U.S. Pat. No. 8,156,086, entitled “Systems And Methods For        Stored Data Verification”.

The information management system 100 can include a variety of differentcomputing devices. For instance, as will be described in greater detailherein, the information management system 100 can include one or moreclient computing devices 102 and secondary storage computing devices106.

Computing devices can include, without limitation, one or more:workstations, personal computers, desktop computers, or other types ofgenerally fixed computing systems such as mainframe computers andminicomputers.

Other computing devices can include mobile or portable computingdevices, such as one or more laptops, tablet computers, personal dataassistants, mobile phones (such as smartphones), and other mobile orportable computing devices such as embedded computers, set top boxes,vehicle-mounted devices, wearable computers, etc. Computing devices caninclude servers, such as mail servers, file servers, database servers,and web servers.

In some cases, a computing device includes virtualized and/or cloudcomputing resources. For instance, one or more virtual machines may beprovided to the organization by a third-party cloud service vendor. Or,in some embodiments, computing devices can include one or more virtualmachine(s) running on a physical host computing device (or “hostmachine”) operated by the organization. As one example, the organizationmay use one virtual machine as a database server and another virtualmachine as a mail server, both virtual machines operating on the samehost machine.

A virtual machine includes an operating system and associated virtualresources, and is hosted simultaneously with another operating system ona physical host computer (or host machine). A hypervisor (typicallysoftware, and also known in the art as a virtual machine monitor or avirtual machine manager or “VMM”) sits between the virtual machine andthe hardware of the physical host computer. One example of hypervisor asvirtualization software is ESX Server, by VMware, Inc. of Palo Alto,Calif.; other examples include Microsoft Virtual Server and MicrosoftWindows Server Hyper-V, both by Microsoft Corporation of Redmond, Wash.,and Sun xVM by Oracle America Inc. of Santa Clara, Calif. In someembodiments, the hypervisor may be firmware or hardware or a combinationof software and/or firmware and/or hardware.

The hypervisor provides to each virtual operating system virtualresources, such as a virtual processor, virtual memory, a virtualnetwork device, and a virtual disk. Each virtual machine has one or morevirtual disks. The hypervisor typically stores the data of virtual disksin files on the file system of the physical host computer, calledvirtual machine disk files (in the case of VMware virtual servers) orvirtual hard disk image files (in the case of Microsoft virtualservers). For example, VMware's ESX Server provides the Virtual MachineFile System (VMFS) for the storage of virtual machine disk files. Avirtual machine reads data from and writes data to its virtual disk muchthe same way that an actual physical machine reads data from and writesdata to an actual disk.

Examples of techniques for implementing information managementtechniques in a cloud computing environment are described in U.S. Pat.No. 8,285,681, which is incorporated by reference herein. Examples oftechniques for implementing information management techniques in avirtualized computing environment are described in U.S. Pat. No.8,307,177, also incorporated by reference herein.

The information management system 100 can also include a variety ofstorage devices, including primary storage devices 104 and secondarystorage devices 108, for example. Storage devices can generally be ofany suitable type including, without limitation, disk drives, hard-diskarrays, semiconductor memory (e.g., solid state storage devices),network attached storage (NAS) devices, tape libraries or othermagnetic, non-tape storage devices, optical media storage devices,DNA/RNA-based memory technology, combinations of the same, and the like.In some embodiments, storage devices can form part of a distributed filesystem. In some cases, storage devices are provided in a cloud (e.g., aprivate cloud or one operated by a third-party vendor). A storage devicein some cases comprises a disk array or portion thereof.

The illustrated information management system 100 includes one or moreclient computing device 102 having at least one application 110executing thereon, and one or more primary storage devices 104 storingprimary data 112. The client computing device(s) 102 and the primarystorage devices 104 may generally be referred to in some cases as aprimary storage subsystem 117. A computing device in an informationmanagement system 100 that has a data agent 142 installed on it isgenerally referred to as a client computing device 102 (or, in thecontext of a component of the information management system 100 simplyas a “client”).

Depending on the context, the term “information management system” canrefer to generally all of the illustrated hardware and softwarecomponents. Or, in other instances, the term may refer to only a subsetof the illustrated components.

For instance, in some cases, the information management system 100generally refers to a combination of specialized components used toprotect, move, manage, manipulate, analyze, and/or process data andmetadata generated by the client computing devices 102. However, theinformation management system 100 in some cases does not include theunderlying components that generate and/or store the primary data 112,such as the client computing devices 102 themselves, the applications110 and operating system residing on the client computing devices 102,and the primary storage devices 104. As an example, “informationmanagement system” may sometimes refer to one or more of the followingcomponents and corresponding data structures: storage managers, dataagents, and media agents. These components will be described in furtherdetail below.

Client Computing Devices

There are typically a variety of sources in an organization that producedata to be protected and managed. As just one illustrative example, in acorporate environment such data sources can be employee workstations andcompany servers such as a mail server, a web server, or the like. In theinformation management system 100, the data generation sources includethe one or more client computing devices 102.

The client computing devices 102 may include any of the types ofcomputing devices described above, without limitation, and in some casesthe client computing devices 102 are associated with one or more usersand/or corresponding user accounts, of employees or other individuals.

The information management system 100 generally addresses and handlesthe data management and protection needs for the data generated by theclient computing devices 102. However, the use of this term does notimply that the client computing devices 102 cannot be “servers” in otherrespects. For instance, a particular client computing device 102 may actas a server with respect to other devices, such as other clientcomputing devices 102. As just a few examples, the client computingdevices 102 can include mail servers, file servers, database servers,and web servers.

Each client computing device 102 may have one or more applications 110(e.g., software applications) executing thereon which generate andmanipulate the data that is to be protected from loss and managed.

The applications 110 generally facilitate the operations of anorganization (or multiple affiliated organizations), and can include,without limitation, mail server applications (e.g., Microsoft ExchangeServer), file server applications, mail client applications (e.g.,Microsoft Exchange Client), database applications (e.g., SQL, Oracle,SAP, Lotus Notes Database), word processing applications (e.g.,Microsoft Word), spreadsheet applications, financial applications,presentation applications, browser applications, mobile applications,entertainment applications, and so on.

The client computing devices 102 can have at least one operating system(e.g., Microsoft Windows, Mac OS X, iOS, IBM z/OS, Linux, otherUnix-based operating systems, etc.) installed thereon, which may supportor host one or more file systems and other applications 110.

As shown, the client computing devices 102 and other components in theinformation management system 100 can be connected to one another viaone or more communication pathways 114. The communication pathways 114can include one or more networks or other connection types including asany of following, without limitation: the Internet, a wide area network(WAN), a local area network (LAN), a Storage Area Network (SAN), a FibreChannel connection, a Small Computer System Interface (SCSI) connection,a virtual private network (VPN), a token ring or TCP/IP based network,an intranet network, a point-to-point link, a cellular network, awireless data transmission system, a two-way cable system, aninteractive kiosk network, a satellite network, a broadband network, abaseband network, a neural network, a mesh network, an ad hoc network,other appropriate wired, wireless, or partially wired/wireless computeror telecommunications networks, combinations of the same or the like.The communication pathways 114 in some cases may also includeapplication programming interfaces (APIs) including, e.g., cloud serviceprovider APIs, virtual machine management APIs, and hosted serviceprovider APIs.

Primary Data and Exemplary Primary Storage Devices

Primary data 112 according to some embodiments is production data orother “live” data generated by the operating system and otherapplications 110 residing on a client computing device 102. The primarydata 112 is generally stored on the primary storage device(s) 104 and isorganized via a file system supported by the client computing device102. For instance, the client computing device(s) 102 and correspondingapplications 110 may create, access, modify, write, delete, andotherwise use primary data 112. In some cases, some or all of theprimary data 112 can be stored in cloud storage resources.

Primary data 112 is generally in the native format of the sourceapplication 110. According to certain aspects, primary data 112 is aninitial or first (e.g., created before any other copies or before atleast one other copy) stored copy of data generated by the sourceapplication 110. Primary data 112 in some cases is created substantiallydirectly from data generated by the corresponding source applications110.

The primary data 112 may sometimes be referred to as a “primary copy” inthe sense that it is a discrete set of data. However, the use of thisterm does not necessarily imply that the “primary copy” is a copy in thesense that it was copied or otherwise derived from another storedversion.

The primary storage devices 104 storing the primary data 112 may berelatively fast and/or expensive (e.g., a disk drive, a hard-disk array,solid state memory, etc.). In addition, primary data 112 may be intendedfor relatively short term retention (e.g., several hours, days, orweeks).

According to some embodiments, the client computing device 102 canaccess primary data 112 from the primary storage device 104 by makingconventional file system calls via the operating system. Primary data112 representing files may include structured data (e.g., databasefiles), unstructured data (e.g., documents), and/or semi-structureddata. Some specific examples are described below with respect to FIG.1B.

It can be useful in performing certain tasks to organize the primarydata 112 into units of different granularities. In general, primary data112 can include files, directories, file system volumes, data blocks,extents, or any other hierarchies or organizations of data objects. Asused herein, a “data object” can refer to both (1) any file that iscurrently addressable by a file system or that was previouslyaddressable by the file system (e.g., an archive file) and (2) a subsetof such a file (e.g., a data block).

As will be described in further detail, it can also be useful inperforming certain functions of the information management system 100 toaccess and modify metadata within the primary data 112. Metadatagenerally includes information about data objects or characteristicsassociated with the data objects.

Metadata can include, without limitation, one or more of the following:the data owner (e.g., the client or user that generates the data), thelast modified time (e.g., the time of the most recent modification ofthe data object), a data object name (e.g., a file name), a data objectsize (e.g., a number of bytes of data), information about the content(e.g., an indication as to the existence of a particular search term),user-supplied tags, to/from information for email (e.g., an emailsender, recipient, etc.), creation date, file type (e.g., format orapplication type), last accessed time, application type (e.g., type ofapplication that generated the data object), location/network (e.g., acurrent, past or future location of the data object and network pathwaysto/from the data object), geographic location (e.g., GPS coordinates),frequency of change (e.g., a period in which the data object ismodified), business unit (e.g., a group or department that generates,manages or is otherwise associated with the data object), aginginformation (e.g., a schedule, such as a time period, in which the dataobject is migrated to secondary or long term storage), boot sectors,partition layouts, file location within a file folder directorystructure, user permissions, owners, groups, access control lists[ACLs]), system metadata (e.g., registry information), combinations ofthe same or the other similar information related to the data object.

In addition to metadata generated by or related to file systems andoperating systems, some of the applications 110 and/or other componentsof the information management system 100 maintain indices of metadatafor data objects, e.g., metadata associated with individual emailmessages. Thus, each data object may be associated with correspondingmetadata. The use of metadata to perform classification and otherfunctions is described in greater detail below.

Each of the client computing devices 102 are generally associated withand/or in communication with one or more of the primary storage devices104 storing corresponding primary data 112. A client computing device102 may be considered to be “associated with” or “in communication with”a primary storage device 104 if it is capable of one or more of: routingand/or storing data to the particular primary storage device 104,coordinating the routing and/or storing of data to the particularprimary storage device 104, retrieving data from the particular primarystorage device 104, coordinating the retrieval of data from theparticular primary storage device 104, and modifying and/or deletingdata retrieved from the particular primary storage device 104.

The primary storage devices 104 can include any of the different typesof storage devices described above, or some other kind of suitablestorage device. The primary storage devices 104 may have relatively fastI/O times and/or are relatively expensive in comparison to the secondarystorage devices 108. For example, the information management system 100may generally regularly access data and metadata stored on primarystorage devices 104, whereas data and metadata stored on the secondarystorage devices 108 is accessed relatively less frequently.

In some cases, each primary storage device 104 is dedicated to anassociated client computing device 102. For instance, a primary storagedevice 104 in one embodiment is a local disk drive of a correspondingclient computing device 102. In other cases, one or more primary storagedevices 104 can be shared by multiple client computing devices 102,e.g., via a network such as in a cloud storage implementation. As oneexample, a primary storage device 104 can be a disk array shared by agroup of client computing devices 102, such as one of the followingtypes of disk arrays: EMC Clariion, EMC Symmetrix, EMC Celerra, DellEqualLogic, IBM XIV, NetApp FAS, HP EVA, and HP 3PAR.

The information management system 100 may also include hosted services(not shown), which may be hosted in some cases by an entity other thanthe organization that employs the other components of the informationmanagement system 100. For instance, the hosted services may be providedby various online service providers to the organization. Such serviceproviders can provide services including social networking services,hosted email services, or hosted productivity applications or otherhosted applications).

Hosted services may include software-as-a-service (SaaS),platform-as-a-service (PaaS), application service providers (ASPs),cloud services, or other mechanisms for delivering functionality via anetwork. As it provides services to users, each hosted service maygenerate additional data and metadata under management of theinformation management system 100, e.g., as primary data 112. In somecases, the hosted services may be accessed using one of the applications110. As an example, a hosted mail service may be accessed via browserrunning on a client computing device 102. The hosted services may beimplemented in a variety of computing environments. In some cases, theyare implemented in an environment having a similar arrangement to theinformation management system 100, where various physical and logicalcomponents are distributed over a network.

Secondary Copies and Exemplary Secondary Storage Devices

The primary data 112 stored on the primary storage devices 104 may becompromised in some cases, such as when an employee deliberately oraccidentally deletes or overwrites primary data 112 during their normalcourse of work. Or the primary storage devices 104 can be damaged orotherwise corrupted.

For recovery and/or regulatory compliance purposes, it is thereforeuseful to generate copies of the primary data 112. Accordingly, theinformation management system 100 includes one or more secondary storagecomputing devices 106 and one or more secondary storage devices 108configured to create and store one or more secondary copies 116 of theprimary data 112 and associated metadata. The secondary storagecomputing devices 106 and the secondary storage devices 108 maysometimes be referred to as a secondary storage subsystem 118.

Creation of secondary copies 116 can help in search and analysis effortsand meet other information management goals, such as: restoring dataand/or metadata if an original version (e.g., of primary data 112) islost (e.g., by deletion, corruption, or disaster); allowingpoint-in-time recovery; complying with regulatory data retention andelectronic discovery (e-discovery) requirements; reducing utilizedstorage capacity; facilitating organization and search of data;improving user access to data files across multiple computing devicesand/or hosted services; and implementing data retention policies.

The client computing devices 102 access or receive primary data 112 andcommunicate the data, e.g., over the communication pathways 114, forstorage in the secondary storage device(s) 108.

A secondary copy 116 can comprise a separate stored copy of applicationdata that is derived from one or more earlier-created, stored copies(e.g., derived from primary data 112 or another secondary copy 116).Secondary copies 116 can include point-in-time data, and may be intendedfor relatively long-term retention (e.g., weeks, months or years),before some or all of the data is moved to other storage or isdiscarded.

In some cases, a secondary copy 116 is a copy of application datacreated and stored subsequent to at least one other stored instance(e.g., subsequent to corresponding primary data 112 or to anothersecondary copy 116), in a different storage device than at least oneprevious stored copy, and/or remotely from at least one previous storedcopy. In some other cases, secondary copies can be stored in the samestorage device as primary data 112 and/or other previously storedcopies. For example, in one embodiment a disk array capable ofperforming hardware snapshots stores primary data 112 and creates andstores hardware snapshots of the primary data 112 as secondary copies116. Secondary copies 116 may be stored in relatively slow and/or lowcost storage (e.g., magnetic tape). A secondary copy 116 may be storedin a backup or archive format, or in some other format different thanthe native source application format or other primary data format.

In some cases, secondary copies 116 are indexed so users can browse andrestore at another point in time. After creation of a secondary copy 116representative of certain primary data 112, a pointer or other locationindicia (e.g., a stub) may be placed in primary data 112, or beotherwise associated with primary data 112 to indicate the currentlocation on the secondary storage device(s) 108.

Since an instance of a data object or metadata in primary data 112 maychange over time as it is modified by an application 110 (or hostedservice or the operating system), the information management system 100may create and manage multiple secondary copies 116 of a particular dataobject or metadata, each representing the state of the data object inprimary data 112 at a particular point in time. Moreover, since aninstance of a data object in primary data 112 may eventually be deletedfrom the primary storage device 104 and the file system, the informationmanagement system 100 may continue to manage point-in-timerepresentations of that data object, even though the instance in primarydata 112 no longer exists.

For virtualized computing devices the operating system and otherapplications 110 of the client computing device(s) 102 may executewithin or under the management of virtualization software (e.g., a VMM),and the primary storage device(s) 104 may comprise a virtual diskcreated on a physical storage device. The information management system100 may create secondary copies 116 of the files or other data objectsin a virtual disk file and/or secondary copies 116 of the entire virtualdisk file itself (e.g., of an entire .vmdk file).

Secondary copies 116 may be distinguished from corresponding primarydata 112 in a variety of ways, some of which will now be described.First, as discussed, secondary copies 116 can be stored in a differentformat (e.g., backup, archive, or other non-native format) than primarydata 112. For this or other reasons, secondary copies 116 may not bedirectly useable by the applications 110 of the client computing device102, e.g., via standard system calls or otherwise without modification,processing, or other intervention by the information management system100.

Secondary copies 116 are also in some embodiments stored on a secondarystorage device 108 that is inaccessible to the applications 110 runningon the client computing devices 102 (and/or hosted services). Somesecondary copies 116 may be “offline copies,” in that they are notreadily available (e.g., not mounted to tape or disk). Offline copiescan include copies of data that the information management system 100can access without human intervention (e.g., tapes within an automatedtape library, but not yet mounted in a drive), and copies that theinformation management system 100 can access only with at least somehuman intervention (e.g., tapes located at an offsite storage site).

The Use of Intermediate Devices For Creating Secondary Copies

Creating secondary copies can be a challenging task. For instance, therecan be hundreds or thousands of client computing devices 102 continuallygenerating large volumes of primary data 112 to be protected. Also,there can be significant overhead involved in the creation of secondarycopies 116. Moreover, secondary storage devices 108 may be specialpurpose components, and interacting with them can require specializedintelligence.

In some cases, the client computing devices 102 interact directly withthe secondary storage device 108 to create the secondary copies 116.However, in view of the factors described above, this approach cannegatively impact the ability of the client computing devices 102 toserve the applications 110 and produce primary data 112. Further, theclient computing devices 102 may not be optimized for interaction withthe secondary storage devices 108.

Thus, in some embodiments, the information management system 100includes one or more software and/or hardware components which generallyact as intermediaries between the client computing devices 102 and thesecondary storage devices 108. In addition to off-loading certainresponsibilities from the client computing devices 102, theseintermediate components can provide other benefits. For instance, asdiscussed further below with respect to FIG. 1D, distributing some ofthe work involved in creating secondary copies 116 can enhancescalability.

The intermediate components can include one or more secondary storagecomputing devices 106 as shown in FIG. 1A and/or one or more mediaagents, which can be software modules residing on correspondingsecondary storage computing devices 106 (or other appropriate devices).Media agents are discussed below (e.g., with respect to FIGS. 1C-1E).

The secondary storage computing device(s) 106 can comprise any of thecomputing devices described above, without limitation. In some cases,the secondary storage computing device(s) 106 include specializedhardware and/or software componentry for interacting with the secondarystorage devices 108.

To create a secondary copy 116 involving the copying of data from theprimary storage subsystem 117 to the secondary storage subsystem 118,the client computing device 102 in some embodiments communicates theprimary data 112 to be copied (or a processed version thereof) to thedesignated secondary storage computing device 106, via the communicationpathway 114. The secondary storage computing device 106 in turn conveysthe received data (or a processed version thereof) to the secondarystorage device 108. In some such configurations, the communicationpathway 114 between the client computing device 102 and the secondarystorage computing device 106 comprises a portion of a LAN, WAN or SAN.In other cases, at least some client computing devices 102 communicatedirectly with the secondary storage devices 108 (e.g., via Fibre Channelor SCSI connections). In some other cases, one or more secondary copies116 are created from existing secondary copies, such as in the case ofan auxiliary copy operation, described in greater detail below.

Exemplary Primary Data and an Exemplary Secondary Copy

FIG. 1B is a detailed view showing some specific examples of primarydata stored on the primary storage device(s) 104 and secondary copy datastored on the secondary storage device(s) 108, with other components inthe system removed for the purposes of illustration. Stored on theprimary storage device(s) 104 are primary data objects including wordprocessing documents 119A-B, spreadsheets 120, presentation documents122, video files 124, image files 126, email mailboxes 128 (andcorresponding email messages 129A-C), html/xml or other types of markuplanguage files 130, databases 132 and corresponding tables or other datastructures 133A-133C).

Some or all primary data objects are associated with correspondingmetadata (e.g., “Meta1-11”), which may include file system metadataand/or application specific metadata. Stored on the secondary storagedevice(s) 108 are secondary copy data objects 134A-C which may includecopies of or otherwise represent corresponding primary data objects andmetadata.

As shown, the secondary copy data objects 134A-C can individuallyrepresent more than one primary data object. For example, secondary copydata object 134A represents three separate primary data objects 133C,122 and 129C (represented as 133C′, 122′ and 129C′, respectively, andaccompanied by the corresponding metadata Meta11, Meta3, and Meta8,respectively). Moreover, as indicated by the prime mark (′), a secondarycopy object may store a representation of a primary data object ormetadata differently than the original format, e.g., in a compressed,encrypted, deduplicated, or other modified format. Likewise, secondarydata object 134B represents primary data objects 120, 133B, and 119A as120′, 133B′, and 119A′, respectively and accompanied by correspondingmetadata Meta2, Meta10, and Meta1, respectively. Also, secondary dataobject 134C represents primary data objects 133A, 119B, and 129A as133A′, 119B′, and 129A′, respectively, accompanied by correspondingmetadata Meta9, Meta5, and Meta6, respectively.

Exemplary Information Management System Architecture

The information management system 100 can incorporate a variety ofdifferent hardware and software components, which can in turn beorganized with respect to one another in many different configurations,depending on the embodiment. There are critical design choices involvedin specifying the functional responsibilities of the components and therole of each component in the information management system 100. Forinstance, as will be discussed, such design choices can impactperformance as well as the adaptability of the information managementsystem 100 to data growth or other changing circumstances.

FIG. 1C shows an information management system 100 designed according tothese considerations and which includes: storage manager 140, acentralized storage and/or information manager that is configured toperform certain control functions, one or more data agents 142 executingon the client computing device(s) 102 configured to process primary data112, and one or more media agents 144 executing on the one or moresecondary storage computing devices 106 for performing tasks involvingthe secondary storage devices 108. While distributing functionalityamongst multiple computing devices can have certain advantages, in othercontexts it can be beneficial to consolidate functionality on the samecomputing device. As such, in various other embodiments, one or more ofthe components shown in FIG. 10 as being implemented on separatecomputing devices are implemented on the same computing device. In oneconfiguration, a storage manager 140, one or more data agents 142, andone or more media agents 144 are all implemented on the same computingdevice. In another embodiment, one or more data agents 142 and one ormore media agents 144 are implemented on the same computing device,while the storage manager 140 is implemented on a separate computingdevice.

Storage Manager

As noted, the number of components in the information management system100 and the amount of data under management can be quite large. Managingthe components and data is therefore a significant task, and a task thatcan grow in an often unpredictable fashion as the quantity of componentsand data scale to meet the needs of the organization.

For these and other reasons, according to certain embodiments,responsibility for controlling the information management system 100, orat least a significant portion of that responsibility, is allocated tothe storage manager 140.

By distributing control functionality in this manner, the storagemanager 140 can be adapted independently according to changingcircumstances. Moreover, a computing device for hosting the storagemanager 140 can be selected to best suit the functions of the storagemanager 140. These and other advantages are described in further detailbelow with respect to FIG. 1D.

The storage manager 140 may be a software module or other application.In some embodiments, storage manager 140 is a computing devicecomprising circuitry for executing computer instructions and performsthe functions described herein. The storage manager generally initiates,performs, coordinates and/or controls storage and other informationmanagement operations performed by the information management system100, e.g., to protect and control the primary data 112 and secondarycopies 116 of data and metadata.

As shown by the dashed arrowed lines 114, the storage manager 140 maycommunicate with and/or control some or all elements of the informationmanagement system 100, such as the data agents 142 and media agents 144.Thus, in certain embodiments, control information originates from thestorage manager 140, whereas payload data and payload metadata isgenerally communicated between the data agents 142 and the media agents144 (or otherwise between the client computing device(s) 102 and thesecondary storage computing device(s) 106), e.g., at the direction ofthe storage manager 140. Control information can generally includeparameters and instructions for carrying out information managementoperations, such as, without limitation, instructions to perform a taskassociated with an operation, timing information specifying when toinitiate a task associated with an operation, data path informationspecifying what components to communicate with or access in carrying outan operation, and the like. Payload data, on the other hand, can includethe actual data involved in the storage operation, such as content datawritten to a secondary storage device 108 in a secondary copy operation.Payload metadata can include any of the types of metadata describedherein, and may be written to a storage device along with the payloadcontent data (e.g., in the form of a header).

In other embodiments, some information management operations arecontrolled by other components in the information management system 100(e.g., the media agent(s) 144 or data agent(s) 142), instead of or incombination with the storage manager 140.

-   -   According to certain embodiments, the storage manager 140        provides one or more of the following functions:    -   initiating execution of secondary copy operations;    -   managing secondary storage devices 108 and inventory/capacity of        the same;    -   reporting, searching, and/or classification of data in the        information management system 100;    -   allocating secondary storage devices 108 for secondary storage        operations;    -   monitoring completion of and providing status reporting related        to secondary storage operations;    -   tracking age information relating to secondary copies 116,        secondary storage devices 108, and comparing the age information        against retention guidelines;    -   tracking movement of data within the information management        system 100;    -   tracking logical associations between components in the        information management system 100;    -   protecting metadata associated with the information management        system 100; and    -   implementing operations management functionality.

The storage manager 140 may maintain a database 146 (or “storage managerdatabase 146” or “management database 146”) of management-related dataand information management policies 148. The database 146 may include amanagement index 150 (or “index 150”) or other data structure thatstores logical associations between components of the system, userpreferences and/or profiles (e.g., preferences regarding encryption,compression, or deduplication of primary or secondary copy data,preferences regarding the scheduling, type, or other aspects of primaryor secondary copy or other operations, mappings of particularinformation management users or user accounts to certain computingdevices or other components, etc.), management tasks, mediacontainerization, or other useful data. For example, the storage manager140 may use the index 150 to track logical associations between mediaagents 144 and secondary storage devices 108 and/or movement of datafrom primary storage devices 104 to secondary storage devices 108. Forinstance, the index 150 may store data associating a client computingdevice 102 with a particular media agent 144 and/or secondary storagedevice 108, as specified in an information management policy 148 (e.g.,a storage policy, which is defined in more detail below).

Administrators and other employees may be able to manually configure andinitiate certain information management operations on an individualbasis. But while this may be acceptable for some recovery operations orother relatively less frequent tasks, it is often not workable forimplementing on-going organization-wide data protection and management.

Thus, the information management system 100 may utilize informationmanagement policies 148 for specifying and executing informationmanagement operations (e.g., on an automated basis). Generally, aninformation management policy 148 can include a data structure or otherinformation source that specifies a set of parameters (e.g., criteriaand rules) associated with storage or other information managementoperations.

The storage manager database 146 may maintain the information managementpolicies 148 and associated data, although the information managementpolicies 148 can be stored in any appropriate location. For instance, aninformation management policy 148 such as a storage policy may be storedas metadata in a media agent database 152 or in a secondary storagedevice 108 (e.g., as an archive copy) for use in restore operations orother information management operations, depending on the embodiment.Information management policies 148 are described further below.

According to certain embodiments, the storage manager database 146comprises a relational database (e.g., an SQL database) for trackingmetadata, such as metadata associated with secondary copy operations(e.g., what client computing devices 102 and corresponding data wereprotected). This and other metadata may additionally be stored in otherlocations, such as at the secondary storage computing devices 106 or onthe secondary storage devices 108, allowing data recovery without theuse of the storage manager 140.

As shown, the storage manager 140 may include a jobs agent 156, a userinterface 158, and a management agent 154, all of which may beimplemented as interconnected software modules or application programs.

The jobs agent 156 in some embodiments initiates, controls, and/ormonitors the status of some or all storage or other informationmanagement operations previously performed, currently being performed,or scheduled to be performed by the information management system 100.For instance, the jobs agent 156 may access information managementpolicies 148 to determine when and how to initiate and control secondarycopy and other information management operations, as will be discussedfurther.

The user interface 158 may include information processing and displaysoftware, such as a graphical user interface (“GUI”), an applicationprogram interface (“API”), or other interactive interface(s) throughwhich users and system processes can retrieve information about thestatus of information management operations (e.g., storage operations)or issue instructions to the information management system 100 and itsconstituent components.

Via the user interface 158, users may optionally issue instructions tothe components in the information management system 100 regardingperformance of storage and recovery operations. For example, a user maymodify a schedule concerning the number of pending secondary copyoperations. As another example, a user may employ the GUI to view thestatus of pending storage operations or to monitor the status of certaincomponents in the information management system 100 (e.g., the amount ofcapacity left in a storage device).

An information management “cell” (or “storage operation cell”) maygenerally include a logical and/or physical grouping of a combination ofhardware and software components associated with performing informationmanagement operations on electronic data, typically one storage manager140 and at least one client computing device 102 (comprising dataagent(s) 142) and at least one media agent 144. For instance, thecomponents shown in FIG. 10 may together form an information managementcell. Multiple cells may be organized hierarchically. With thisconfiguration, cells may inherit properties from hierarchically superiorcells or be controlled by other cells in the hierarchy (automatically orotherwise). Alternatively, in some embodiments, cells may inherit orotherwise be associated with information management policies,preferences, information management metrics, or other properties orcharacteristics according to their relative position in a hierarchy ofcells. Cells may also be delineated and/or organized hierarchicallyaccording to function, geography, architectural considerations, or otherfactors useful or desirable in performing information managementoperations. A first cell may represent a geographic segment of anenterprise, such as a Chicago office, and a second cell may represent adifferent geographic segment, such as a New York office. Other cells mayrepresent departments within a particular office. Where delineated byfunction, a first cell may perform one or more first types ofinformation management operations (e.g., one or more first types ofsecondary or other copies), and a second cell may perform one or moresecond types of information management operations (e.g., one or moresecond types of secondary or other copies).

The storage manager 140 may also track information that permits it toselect, designate, or otherwise identify content indices, deduplicationdatabases, or similar databases or resources or data sets within itsinformation management cell (or another cell) to be searched in responseto certain queries. Such queries may be entered by the user viainteraction with the user interface 158. In general, the managementagent 154 allows multiple information management cells to communicatewith one another. For example, the information management system 100 insome cases may be one information management cell of a network ofmultiple cells adjacent to one another or otherwise logically related ina WAN or LAN. With this arrangement, the cells may be connected to oneanother through respective management agents 154.

For instance, the management agent 154 can provide the storage manager140 with the ability to communicate with other components within theinformation management system 100 (and/or other cells within a largerinformation management system) via network protocols and applicationprogramming interfaces (“APIs”) including, e.g., HTTP, HTTPS, FTP, REST,virtualization software APIs, cloud service provider APIs, and hostedservice provider APIs. Inter-cell communication and hierarchy isdescribed in greater detail in U.S. Pat. Nos. 7,747,579 and 7,343,453,which are incorporated by reference herein.

Data Agents

As discussed, a variety of different types of applications 110 canreside on a given client computing device 102, including operatingsystems, database applications, e-mail applications, and virtualmachines, just to name a few. And, as part of the process of creatingand restoring secondary copies 116, the client computing devices 102 maybe tasked with processing and preparing the primary data 112 from thesevarious different applications 110. Moreover, the nature of theprocessing/preparation can differ across clients and application types,e.g., due to inherent structural and formatting differences betweenapplications 110.

The one or more data agent(s) 142 are therefore advantageouslyconfigured in some embodiments to assist in the performance ofinformation management operations based on the type of data that isbeing protected, at a client-specific and/or application-specific level.

The data agent 142 may be a software module or component that isgenerally responsible for managing, initiating, or otherwise assistingin the performance of information management operations. For instance,the data agent 142 may take part in performing data storage operationssuch as the copying, archiving, migrating, replicating of primary data112 stored in the primary storage device(s) 104. The data agent 142 mayreceive control information from the storage manager 140, such ascommands to transfer copies of data objects, metadata, and other payloaddata to the media agents 144.

In some embodiments, a data agent 142 may be distributed between theclient computing device 102 and storage manager 140 (and any otherintermediate components) or may be deployed from a remote location orits functions approximated by a remote process that performs some or allof the functions of data agent 142. In addition, a data agent 142 mayperform some functions provided by a media agent 144, or may performother functions such as encryption and deduplication.

As indicated, each data agent 142 may be specialized for a particularapplication 110, and the system can employ multiple application-specificdata agents 142, each of which may perform information managementoperations (e.g., perform backup, migration, and data recovery)associated with a different application 110. For instance, differentindividual data agents 142 may be designed to handle Microsoft Exchangedata, Lotus Notes data, Microsoft Windows file system data, MicrosoftActive Directory Objects data, SQL Server data, SharePoint data, Oracledatabase data, SAP database data, virtual machines and/or associateddata, and other types of data.

A file system data agent, for example, may handle data files and/orother file system information. If a client computing device 102 has twoor more types of data, one data agent 142 may be used for each data typeto copy, archive, migrate, and restore the client computing device 102data. For example, to backup, migrate, and restore all of the data on aMicrosoft Exchange server, the client computing device 102 may use oneMicrosoft Exchange Mailbox data agent 142 to backup the Exchangemailboxes, one Microsoft Exchange Database data agent 142 to backup theExchange databases, one Microsoft Exchange Public Folder data agent 142to backup the Exchange Public Folders, and one Microsoft Windows FileSystem data agent 142 to backup the file system of the client computingdevice 102. In such embodiments, these data agents 142 may be treated asfour separate data agents 142 even though they reside on the same clientcomputing device 102.

Other embodiments may employ one or more generic data agents 142 thatcan handle and process data from two or more different applications 110,or that can handle and process multiple data types, instead of or inaddition to using specialized data agents 142. For example, one genericdata agent 142 may be used to back up, migrate and restore MicrosoftExchange Mailbox data and Microsoft Exchange Database data while anothergeneric data agent may handle Microsoft Exchange Public Folder data andMicrosoft Windows File System data.

Each data agent 142 may be configured to access data and/or metadatastored in the primary storage device(s) 104 associated with the dataagent 142 and process the data as appropriate. For example, during asecondary copy operation, the data agent 142 may arrange or assemble thedata and metadata into one or more files having a certain format (e.g.,a particular backup or archive format) before transferring the file(s)to a media agent 144 or other component. The file(s) may include a listof files or other metadata. Each data agent 142 can also assist inrestoring data or metadata to primary storage devices 104 from asecondary copy 116. For instance, the data agent 142 may operate inconjunction with the storage manager 140 and one or more of the mediaagents 144 to restore data from secondary storage device(s) 108.

Media Agents

As indicated above with respect to FIG. 1A, off-loading certainresponsibilities from the client computing devices 102 to intermediatecomponents such as the media agent(s) 144 can provide a number ofbenefits including improved client computing device 102 operation,faster secondary copy operation performance, and enhanced scalability.As one specific example which will be discussed below in further detail,the media agent 144 can act as a local cache of copied data and/ormetadata that it has stored to the secondary storage device(s) 108,providing improved restore capabilities.

Generally speaking, a media agent 144 may be implemented as a softwaremodule that manages, coordinates, and facilitates the transmission ofdata, as directed by the storage manager 140, between a client computingdevice 102 and one or more secondary storage devices 108. Whereas thestorage manager 140 controls the operation of the information managementsystem 100, the media agent 144 generally provides a portal to secondarystorage devices 108. For instance, other components in the systeminteract with the media agents 144 to gain access to data stored on thesecondary storage devices 108, whether it be for the purposes ofreading, writing, modifying, or deleting data. Moreover, as will bedescribed further, media agents 144 can generate and store informationrelating to characteristics of the stored data and/or metadata, or cangenerate and store other types of information that generally providesinsight into the contents of the secondary storage devices 108.

Media agents 144 can comprise separate nodes in the informationmanagement system 100 (e.g., nodes that are separate from the clientcomputing devices 102, storage manager 140, and/or secondary storagedevices 108). In general, a node within the information managementsystem 100 can be a logically and/or physically separate component, andin some cases is a component that is individually addressable orotherwise identifiable. In addition, each media agent 144 may reside ona dedicated secondary storage computing device 106 in some cases, whilein other embodiments a plurality of media agents 144 reside on the samesecondary storage computing device 106.

A media agent 144 (and corresponding media agent database 152) may beconsidered to be “associated with” a particular secondary storage device108 if that media agent 144 is capable of one or more of: routing and/orstoring data to the particular secondary storage device 108,coordinating the routing and/or storing of data to the particularsecondary storage device 108, retrieving data from the particularsecondary storage device 108, coordinating the retrieval of data from aparticular secondary storage device 108, and modifying and/or deletingdata retrieved from the particular secondary storage device 108.

While media agent(s) 144 are generally associated with one or moresecondary storage devices 108, one or more media agents 144 in certainembodiments are physically separate from the secondary storage devices108. For instance, the media agents 144 may reside on secondary storagecomputing devices 106 having different housings or packages than thesecondary storage devices 108. In one example, a media agent 144 resideson a first server computer and is in communication with a secondarystorage device(s) 108 residing in a separate, rack-mounted RAID-basedsystem.

Where the information management system 100 includes multiple mediaagents 144 (FIG. 1D), a first media agent 144 may provide failoverfunctionality for a second, failed media agent 144. In addition, mediaagents 144 can be dynamically selected for storage operations to provideload balancing. Failover and load balancing are described in greaterdetail below.

In operation, a media agent 144 associated with a particular secondarystorage device 108 may instruct the secondary storage device 108 toperform an information management operation. For instance, a media agent144 may instruct a tape library to use a robotic arm or other retrievalmeans to load or eject a certain storage media, and to subsequentlyarchive, migrate, or retrieve data to or from that media, e.g., for thepurpose of restoring the data to a client computing device 102. Asanother example, a secondary storage device 108 may include an array ofhard disk drives or solid state drives organized in a RAIDconfiguration, and the media agent 144 may forward a logical unit number(LUN) and other appropriate information to the array, which uses thereceived information to execute the desired storage operation. The mediaagent 144 may communicate with a secondary storage device 108 via asuitable communications link, such as a SCSI or Fiber Channel link.

As shown, each media agent 144 may maintain an associated media agentdatabase 152. The media agent database 152 may be stored in a disk orother storage device (not shown) that is local to the secondary storagecomputing device 106 on which the media agent 144 resides. In othercases, the media agent database 152 is stored remotely from thesecondary storage computing device 106.

The media agent database 152 can include, among other things, an index153 including data generated during secondary copy operations and otherstorage or information management operations. The index 153 provides amedia agent 144 or other component with a fast and efficient mechanismfor locating secondary copies 116 or other data stored in the secondarystorage devices 108. In some cases, the index 153 does not form a partof and is instead separate from the media agent database 152.

A media agent index 153 or other data structure associated with theparticular media agent 144 may include information about the storeddata. For instance, for each secondary copy 116, the index 153 mayinclude metadata such as a list of the data objects (e.g.,files/subdirectories, database objects, mailbox objects, etc.), a pathto the secondary copy 116 on the corresponding secondary storage device108, location information indicating where the data objects are storedin the secondary storage device 108, when the data objects were createdor modified, etc. Thus, the index 153 includes metadata associated withthe secondary copies 116 that is readily available for use in storageoperations and other activities without having to be first retrievedfrom the secondary storage device 108. In yet further embodiments, someor all of the data in the index 153 may instead or additionally bestored along with the data in a secondary storage device 108, e.g., witha copy of the index 153. In some embodiments, the secondary storagedevices 108 can include sufficient information to perform a “bare metalrestore”, where the operating system of a failed client computing device102 or other restore target is automatically rebuilt as part of arestore operation.

Because the index 153 maintained in the media agent database 152 mayoperate as a cache, it can also be referred to as “an index cache.” Insuch cases, information stored in the index cache 153 typicallycomprises data that reflects certain particulars about storageoperations that have occurred relatively recently. After some triggeringevent, such as after a certain period of time elapses, or the indexcache 153 reaches a particular size, the index cache 153 may be copiedor migrated to a secondary storage device(s) 108. This information mayneed to be retrieved and uploaded back into the index cache 153 orotherwise restored to a media agent 144 to facilitate retrieval of datafrom the secondary storage device(s) 108. In some embodiments, thecached information may include format or containerization informationrelated to archives or other files stored on the storage device(s) 108.In this manner, the index cache 153 allows for accelerated restores.

In some alternative embodiments the media agent 144 generally acts as acoordinator or facilitator of storage operations between clientcomputing devices 102 and corresponding secondary storage devices 108,but does not actually write the data to the secondary storage device108. For instance, the storage manager 140 (or the media agent 144) mayinstruct a client computing device 102 and secondary storage device 108to communicate with one another directly. In such a case the clientcomputing device 102 transmits the data directly or via one or moreintermediary components to the secondary storage device 108 according tothe received instructions, and vice versa. In some such cases, the mediaagent 144 may still receive, process, and/or maintain metadata relatedto the storage operations. Moreover, in these embodiments, the payloaddata can flow through the media agent 144 for the purposes of populatingthe index cache 153 maintained in the media agent database 152, but notfor writing to the secondary storage device 108.

The media agent 144 and/or other components such as the storage manager140 may in some cases incorporate additional functionality, such as dataclassification, content indexing, deduplication, encryption,compression, and the like. Further details regarding these and otherfunctions are described below.

Distributed, Scalable Architecture

As described, certain functions of the information management system 100can be distributed amongst various physical and/or logical components inthe system. For instance, one or more of the storage manager 140, dataagents 142, and media agents 144 may reside on computing devices thatare physically separate from one another. This architecture can providea number of benefits.

For instance, hardware and software design choices for each distributedcomponent can be targeted to suit its particular function. The secondarycomputing devices 106 on which the media agents 144 reside can betailored for interaction with associated secondary storage devices 108and provide fast index cache operation, among other specific tasks.Similarly, the client computing device(s) 102 can be selected toeffectively service the applications 110 residing thereon, in order toefficiently produce and store primary data 112.

Moreover, in some cases, one or more of the individual components in theinformation management system 100 can be distributed to multiple,separate computing devices. As one example, for large file systems wherethe amount of data stored in the database 146 is relatively large, thedatabase 146 may be migrated to or otherwise reside on a specializeddatabase server (e.g., an SQL server) separate from a server thatimplements the other functions of the storage manager 140. Thisconfiguration can provide added protection because the database 146 canbe protected with standard database utilities (e.g., SQL log shipping ordatabase replication) independent from other functions of the storagemanager 140. The database 146 can be efficiently replicated to a remotesite for use in the event of a disaster or other data loss incident atthe primary site. Or the database 146 can be replicated to anothercomputing device within the same site, such as to a higher performancemachine in the event that a storage manager host device can no longerservice the needs of a growing information management system 100.

The distributed architecture also provides both scalability andefficient component utilization. FIG. 1D shows an embodiment of theinformation management system 100 including a plurality of clientcomputing devices 102 and associated data agents 142 as well as aplurality of secondary storage computing devices 106 and associatedmedia agents 144.

Additional components can be added or subtracted based on the evolvingneeds of the information management system 100. For instance, dependingon where bottlenecks are identified, administrators can add additionalclient computing devices 102, secondary storage computing devices 106(and corresponding media agents 144), and/or secondary storage devices108. Moreover, where multiple fungible components are available, loadbalancing can be implemented to dynamically address identifiedbottlenecks. As an example, the storage manager 140 may dynamicallyselect which media agents 144 and/or secondary storage devices 108 touse for storage operations based on a processing load analysis of themedia agents 144 and/or secondary storage devices 108, respectively.

Moreover, each client computing device 102 in some embodiments cancommunicate with, among other components, any of the media agents 144,e.g., as directed by the storage manager 140. And each media agent 144may be able to communicate with, among other components, any of thesecondary storage devices 108, e.g., as directed by the storage manager140. Thus, operations can be routed to the secondary storage devices 108in a dynamic and highly flexible manner, to provide load balancing,failover, and the like. Further examples of scalable systems capable ofdynamic storage operations, and of systems capable of performing loadbalancing and fail over are provided in U.S. Pat. No. 7,246,207, whichis incorporated by reference herein.

In alternative configurations, certain components are not distributedand may instead reside and execute on the same computing device. Forexample, in some embodiments one or more data agents 142 and the storagemanager 140 reside on the same client computing device 102. In anotherembodiment, one or more data agents 142 and one or more media agents 144reside on a single computing device.

Exemplary Types of Information Management Operations

In order to protect and leverage stored data, the information managementsystem 100 can be configured to perform a variety of informationmanagement operations. As will be described, these operations cangenerally include secondary copy and other data movement operations,processing and data manipulation operations, analysis, reporting, andmanagement operations. The operations described herein may be performedon any type of computing platform, e.g., between two computers connectedvia a LAN, to a mobile client telecommunications device connected to aserver via a WLAN, to any manner of client device coupled to a cloudstorage target.

Data Movement Operations

Data movement operations according to certain embodiments are generallyoperations that involve the copying or migration of data (e.g., payloaddata) between different locations in the information management system100 in an original/native and/or one or more different formats. Forexample, data movement operations can include operations in which storeddata is copied, migrated, or otherwise transferred from one or morefirst storage devices to one or more second storage devices, such asfrom primary storage device(s) 104 to secondary storage device(s) 108,from secondary storage device(s) 108 to different secondary storagedevice(s) 108, from secondary storage devices 108 to primary storagedevices 104, or from primary storage device(s) 104 to different primarystorage device(s) 104.

Data movement operations can include by way of example, backupoperations, archive operations, information lifecycle managementoperations such as hierarchical storage management operations,replication operations (e.g., continuous data replication operations),snapshot operations, deduplication or single-instancing operations,auxiliary copy operations, and the like. As will be discussed, some ofthese operations involve the copying, migration or other movement ofdata, without actually creating multiple, distinct copies. Nonetheless,some or all of these operations are referred to as “copy” operations forsimplicity.

Backup Operations

A backup operation creates a copy of a version of data (e.g., one ormore files or other data units) in primary data 112 at a particularpoint in time. Each subsequent backup copy may be maintainedindependently of the first. Further, a backup copy in some embodimentsis generally stored in a form that is different than the native format,e.g., a backup format. This can be in contrast to the version in primarydata 112 from which the backup copy is derived, and which may instead bestored in a native format of the source application(s) 110. In variouscases, backup copies can be stored in a format in which the data iscompressed, encrypted, deduplicated, and/or otherwise modified from theoriginal application format. For example, a backup copy may be stored ina backup format that facilitates compression and/or efficient long-termstorage.

Backup copies can have relatively long retention periods as compared toprimary data 112, and may be stored on media with slower retrieval timesthan primary data 112 and certain other types of secondary copies 116.On the other hand, backups may have relatively shorter retention periodsthan some other types of secondary copies 116, such as archive copies(described below). Backups may sometimes be stored at on offsitelocation.

Backup operations can include full, synthetic or incremental backups. Afull backup in some embodiments is generally a complete image of thedata to be protected. However, because full backup copies can consume arelatively large amount of storage, it can be useful to use a fullbackup copy as a baseline and only store changes relative to the fullbackup copy for subsequent backup copies.

For instance, a differential backup operation (or cumulative incrementalbackup operation) tracks and stores changes that have occurred since thelast full backup. Differential backups can grow quickly in size, but canprovide relatively efficient restore times because a restore can becompleted in some cases using only the full backup copy and the latestdifferential copy.

An incremental backup operation generally tracks and stores changessince the most recent backup copy of any type, which can greatly reducestorage utilization. In some cases, however, restore times can berelatively long in comparison to full or differential backups becausecompleting a restore operation may involve accessing a full backup inaddition to multiple incremental backups.

Any of the above types of backup operations can be at the volume-level,file-level, or block-level. Volume level backup operations generallyinvolve the copying of a data volume (e.g., a logical disk or partition)as a whole. In a file-level backup, the information management system100 may generally track changes to individual files at the file-level,and includes copies of files in the backup copy. In the case of ablock-level backup, files are broken into constituent blocks, andchanges are tracked at the block-level. Upon restore, the informationmanagement system 100 reassembles the blocks into files in a transparentfashion.

Far less data may actually be transferred and copied to the secondarystorage devices 108 during a file-level copy than a volume-level copy.Likewise, a block-level copy may involve the transfer of less data thana file-level copy, resulting in faster execution times. However,restoring a relatively higher-granularity copy can result in longerrestore times. For instance, when restoring a block-level copy, theprocess of locating constituent blocks can sometimes result in longerrestore times as compared to file-level backups. Similar to backupoperations, the other types of secondary copy operations describedherein can also be implemented at either the volume-level, file-level,or block-level.

Archive Operations

Because backup operations generally involve maintaining a version of thecopied data in primary data 112 and also maintaining backup copies insecondary storage device(s) 108, they can consume significant storagecapacity. To help reduce storage consumption, an archive operationaccording to certain embodiments creates a secondary copy 116 by bothcopying and removing source data. Or, seen another way, archiveoperations can involve moving some or all of the source data to thearchive destination. Thus, data satisfying criteria for removal (e.g.,data of a threshold age or size) from the source copy may be removedfrom source storage. Archive copies are sometimes stored in an archiveformat or other non-native application format. The source data may beprimary data 112 or a secondary copy 116, depending on the situation. Aswith backup copies, archive copies can be stored in a format in whichthe data is compressed, encrypted, deduplicated, and/or otherwisemodified from the original application format.

In addition, archive copies may be retained for relatively long periodsof time (e.g., years) and, in some cases, are never deleted. Archivecopies are generally retained for longer periods of time than backupcopies, for example. In certain embodiments, archive copies may be madeand kept for extended periods in order to meet compliance regulations.

Moreover, when primary data 112 is archived, in some cases the archivedprimary data 112 or a portion thereof is deleted when creating thearchive copy. Thus, archiving can serve the purpose of freeing up spacein the primary storage device(s) 104. Similarly, when a secondary copy116 is archived, the secondary copy 116 may be deleted, and an archivecopy can therefore serve the purpose of freeing up space in secondarystorage device(s) 108. In contrast, source copies often remain intactwhen creating backup copies. Examples of compatible data archivingoperations are provided in U.S. Pat. No. 7,107,298, which isincorporated by reference herein.

Snapshot Operations

Snapshot operations can provide a relatively lightweight, efficientmechanism for protecting data. From an end-user viewpoint, a snapshotmay be thought of as an “instant” image of the primary data 112 at agiven point in time, and may include state and/or status informationrelative to an application that creates/manages the data. In oneembodiment, a snapshot may generally capture the directory structure ofan object in primary data 112 such as a file or volume or other data setat a particular moment in time and may also preserve file attributes andcontents. A snapshot in some cases is created relatively quickly, e.g.,substantially instantly, using a minimum amount of file space, but maystill function as a conventional file system backup.

A “hardware snapshot” (or “hardware-based snapshot”) operation can be asnapshot operation where a target storage device (e.g., a primarystorage device 104 or a secondary storage device 108) performs thesnapshot operation in a self-contained fashion, substantiallyindependently, using hardware, firmware and/or software residing on thestorage device itself. For instance, the storage device may be capableof performing snapshot operations upon request, generally withoutintervention or oversight from any of the other components in theinformation management system 100. In this manner, hardware snapshotscan off-load other components of information management system 100 fromprocessing involved in snapshot creation and management.

A “software snapshot” (or “software-based snapshot”) operation, on theother hand, can be a snapshot operation in which one or more othercomponents in information management system 100 (e.g., client computingdevices 102, data agents 142, etc.) implement a software layer thatmanages the snapshot operation via interaction with the target storagedevice. For instance, the component implementing the snapshot managementsoftware layer may derive a set of pointers and/or data that representsthe snapshot. The snapshot management software layer may then transmitthe same to the target storage device, along with appropriateinstructions for writing the snapshot.

Some types of snapshots do not actually create another physical copy ofall the data as it existed at the particular point in time, but maysimply create pointers that are able to map files and directories tospecific memory locations (e.g., to specific disk blocks) where the dataresides, as it existed at the particular point in time. For example, asnapshot copy may include a set of pointers derived from the file systemor an application. In some other cases, the snapshot may be created atthe block-level, such as where creation of the snapshot occurs withoutawareness of the file system. Each pointer points to a respective storeddata block, so that collectively, the set of pointers reflect thestorage location and state of the data object (e.g., file(s) orvolume(s) or data set(s)) at a particular point in time when thesnapshot copy was created.

Once a snapshot has been taken, subsequent changes to the file systemtypically do not overwrite the blocks in use at the time of thesnapshot. Therefore, the initial snapshot may use only a small amount ofdisk space needed to record a mapping or other data structurerepresenting or otherwise tracking the blocks that correspond to thecurrent state of the file system. Additional disk space is usuallyrequired only when files and directories are actually later modified.Furthermore, when files are modified, typically only the pointers whichmap to blocks are copied, not the blocks themselves. In someembodiments, for example in the case of “copy-on-write” snapshots, whena block changes in primary storage, the block is copied to secondarystorage or cached in primary storage before the block is overwritten inprimary storage, and the pointer to that block changed to reflect thenew location of that block. The snapshot mapping of file system data mayalso be updated to reflect the changed block(s) at that particular pointin time. In some other cases, a snapshot includes a full physical copyof all or substantially all of the data represented by the snapshot.Further examples of snapshot operations are provided in U.S. Pat. No.7,529,782, which is incorporated by reference herein.

A snapshot copy in many cases can be made quickly and withoutsignificantly impacting primary computing resources because largeamounts of data need not be copied or moved. In some embodiments, asnapshot may exist as a virtual file system, parallel to the actual filesystem. Users in some cases gain read-only access to the record of filesand directories of the snapshot. By electing to restore primary data 112from a snapshot taken at a given point in time, users may also returnthe current file system to the state of the file system that existedwhen the snapshot was taken.

Replication Operations

Another type of secondary copy operation is a replication operation.Some types of secondary copies 116 are used to periodically captureimages of primary data 112 at particular points in time (e.g., backups,archives, and snapshots). However, it can also be useful for recoverypurposes to protect primary data 112 in a more continuous fashion, byreplicating the primary data 112 substantially as changes occur. In somecases a replication copy can be a mirror copy, for instance, wherechanges made to primary data 112 are mirrored or substantiallyimmediately copied to another location (e.g., to secondary storagedevice(s) 108). By copying each write operation to the replication copy,two storage systems are kept synchronized or substantially synchronizedso that they are virtually identical at approximately the same time.Where entire disk volumes are mirrored, however, mirroring can requiresignificant amount of storage space and utilizes a large amount ofprocessing resources.

According to some embodiments storage operations are performed onreplicated data that represents a recoverable state, or “known goodstate” of a particular application running on the source system. Forinstance, in certain embodiments, known good replication copies may beviewed as copies of primary data 112. This feature allows the system todirectly access, copy, restore, backup or otherwise manipulate thereplication copies as if the data was the “live”, primary data 112. Thiscan reduce access time, storage utilization, and impact on sourceapplications 110, among other benefits.

Based on known good state information, the information management system100 can replicate sections of application data that represent arecoverable state rather than rote copying of blocks of data. Examplesof compatible replication operations (e.g., continuous data replication)are provided in U.S. Pat. No. 7,617,262, which is incorporated byreference herein.

Deduplication/Single-Instancing Operations

Another type of data movement operation is deduplication orsingle-instance storage, which is useful to reduce the amount of datawithin the system. For instance, some or all of the above-describedsecondary storage operations can involve deduplication in some fashion.New data is read, broken down into portions (e.g., sub-file levelblocks, files, etc.) of a selected granularity, compared with blocksthat are already stored, and only the new blocks are stored. Blocks thatalready exist are represented as pointers to the already stored data.

In order to streamline the comparison process, the informationmanagement system 100 may calculate and/or store signatures (e.g.,hashes or cryptographically unique IDs) corresponding to the individualdata blocks in a database and compare the signatures instead ofcomparing entire data blocks. In some cases, only a single instance ofeach element is stored, and deduplication operations may therefore bereferred to interchangeably as “single-instancing” operations. Dependingon the implementation, however, deduplication or single-instancingoperations can store more than one instance of certain data blocks, butnonetheless significantly reduce data redundancy.

Depending on the embodiment, deduplication blocks can be of fixed orvariable length. Using variable length blocks can provide enhanceddeduplication by responding to changes in the data stream, but caninvolve complex processing. In some cases, the information managementsystem 100 utilizes a technique for dynamically aligning deduplicationblocks (e.g., fixed-length blocks) based on changing content in the datastream, as described in U.S. Pat. No. 8,364,652, which is incorporatedby reference herein.

The information management system 100 can perform deduplication in avariety of manners at a variety of locations in the informationmanagement system 100. For instance, in some embodiments, theinformation management system 100 implements “target-side” deduplicationby deduplicating data (e.g., secondary copies 116) stored in thesecondary storage devices 108. In some such cases, the media agents 144are generally configured to manage the deduplication process. Forinstance, one or more of the media agents 144 maintain a correspondingdeduplication database that stores deduplication information (e.g.,datablock signatures). Examples of such a configuration are provided inU.S. Pat. Pub. No. 2012/0150826, which is incorporated by referenceherein. Instead of or in combination with “target-side” deduplication,deduplication can also be performed on the “source-side” (or“client-side”), e.g., to reduce the amount of traffic between the mediaagents 144 and the client computing device(s) 102 and/or reduceredundant data stored in the primary storage devices 104. According tovarious implementations, one or more of the storage devices of thetarget-side, source-side, or client-side of an operation can becloud-based storage devices. Thus, the target-side, source-side, and/orclient-side deduplication can be cloud-based deduplication. Inparticular, as discussed previously, the storage manager 140 maycommunicate with other components within the information managementsystem 100 via network protocols and cloud service provider APIs tofacilitate cloud-based deduplication/single instancing. Examples of suchdeduplication techniques are provided in U.S. Pat. Pub. No.2012/0150818, which is incorporated by reference herein. Some othercompatible deduplication/single instancing techniques are described inU.S. Pat. Pub. Nos. 2006/0224846 and 2009/0319534, which areincorporated by reference herein.

Information Lifecycle Management and Hierarchical Storage ManagementOperations

In some embodiments, files and other data over their lifetime move frommore expensive, quick access storage to less expensive, slower accessstorage. Operations associated with moving data through various tiers ofstorage are sometimes referred to as information lifecycle management(ILM) operations.

One type of ILM operation is a hierarchical storage management (HSM)operation. A HSM operation is generally an operation for automaticallymoving data between classes of storage devices, such as betweenhigh-cost and low-cost storage devices. For instance, an HSM operationmay involve movement of data from primary storage devices 104 tosecondary storage devices 108, or between tiers of secondary storagedevices 108. With each tier, the storage devices may be progressivelyrelatively cheaper, have relatively slower access/restore times, etc.For example, movement of data between tiers may occur as data becomesless important over time.

In some embodiments, an HSM operation is similar to an archive operationin that creating an HSM copy may (though not always) involve deletingsome of the source data, e.g., according to one or more criteria relatedto the source data. For example, an HSM copy may include data fromprimary data 112 or a secondary copy 116 that is larger than a givensize threshold or older than a given age threshold and that is stored ina backup format.

Often, and unlike some types of archive copies, HSM data that is removedor aged from the source copy is replaced by a logical reference pointeror stub. The reference pointer or stub can be stored in the primarystorage device 104 (or other source storage device, such as a secondarystorage device 108) to replace the deleted data in primary data 112 (orother source copy) and to point to or otherwise indicate the newlocation in a secondary storage device 108.

According to one example, files are generally moved between higher andlower cost storage depending on how often the files are accessed. When auser requests access to the HSM data that has been removed or migrated,the information management system 100 uses the stub to locate the dataand often make recovery of the data appear transparent, even though theHSM data may be stored at a location different from the remaining sourcedata. In this manner, the data appears to the user (e.g., in file systembrowsing windows and the like) as if it still resides in the sourcelocation (e.g., in a primary storage device 104). The stub may alsoinclude some metadata associated with the corresponding data, so that afile system and/or application can provide some information about thedata object and/or a limited-functionality version (e.g., a preview) ofthe data object.

An HSM copy may be stored in a format other than the native applicationformat (e.g., where the data is compressed, encrypted, deduplicated,and/or otherwise modified from the original application format). In somecases, copies which involve the removal of data from source storage andthe maintenance of stub or other logical reference information on sourcestorage may be referred to generally as “on-line archive copies”. On theother hand, copies which involve the removal of data from source storagewithout the maintenance of stub or other logical reference informationon source storage may be referred to as “off-line archive copies”.Examples of HSM and ILM techniques are provided in U.S. Pat. No.7,343,453, which is incorporated by reference herein.

Auxiliary Copy and Disaster Recovery Operations

An auxiliary copy is generally a copy operation in which a copy iscreated of an existing secondary copy 116. For instance, an initialsecondary copy 116 may be generated using or otherwise be derived fromprimary data 112 (or other data residing in the secondary storagesubsystem 118), whereas an auxiliary copy is generated from the initialsecondary copy 116. Auxiliary copies can be used to create additionalstandby copies of data and may reside on different secondary storagedevices 108 than the initial secondary copies 116. Thus, auxiliarycopies can be used for recovery purposes if initial secondary copies 116become unavailable. Exemplary compatible auxiliary copy techniques aredescribed in further detail in U.S. Pat. No. 8,230,195, which isincorporated by reference herein.

The information management system 100 may also perform disaster recoveryoperations that make or retain disaster recovery copies, often assecondary, high-availability disk copies. The information managementsystem 100 may create secondary disk copies and store the copies atdisaster recovery locations using auxiliary copy or replicationoperations, such as continuous data replication technologies. Dependingon the particular data protection goals, disaster recovery locations canbe remote from the client computing devices 102 and primary storagedevices 104, remote from some or all of the secondary storage devices108, or both.

Data Analysis, Reporting, and Management Operations

Data analysis, reporting, and management operations can be differentthan data movement operations in that they do not necessarily involvethe copying, migration or other transfer of data (e.g., primary data 112or secondary copies 116) between different locations in the system. Forinstance, data analysis operations may involve processing (e.g., offlineprocessing) or modification of already stored primary data 112 and/orsecondary copies 116. However, in some embodiments data analysisoperations are performed in conjunction with data movement operations.Some data analysis operations include content indexing operations andclassification operations which can be useful in leveraging the dataunder management to provide enhanced search and other features. Otherdata analysis operations such as compression and encryption can providedata reduction and security benefits, respectively.

Classification Operations/Content Indexing

In some embodiments, the information management system 100 analyzes andindexes characteristics, content, and metadata associated with the datastored within the primary data 112 and/or secondary copies 116,providing enhanced search and management capabilities for data discoveryand other purposes. The content indexing can be used to identify filesor other data objects having pre-defined content (e.g., user-definedkeywords or phrases, other keywords/phrases that are not defined by auser, etc.), and/or metadata (e.g., email metadata such as “to”, “from”,“cc”, “bcc”, attachment name, received time, etc.).

The information management system 100 generally organizes and cataloguesthe results in a content index, which may be stored within the mediaagent database 152, for example. The content index can also include thestorage locations of (or pointer references to) the indexed data in theprimary data 112 or secondary copies 116, as appropriate. The resultsmay also be stored, in the form of a content index database orotherwise, elsewhere in the information management system 100 (e.g., inthe primary storage devices 104, or in the secondary storage device108). Such index data provides the storage manager 140 or anothercomponent with an efficient mechanism for locating primary data 112and/or secondary copies 116 of data objects that match particularcriteria.

For instance, search criteria can be specified by a user through userinterface 158 of the storage manager 140. In some cases, the informationmanagement system 100 analyzes data and/or metadata in secondary copies116 to create an “off-line” content index, without significantlyimpacting the performance of the client computing devices 102. Dependingon the embodiment, the system can also implement “on-line” contentindexing, e.g., of primary data 112. Examples of compatible contentindexing techniques are provided in U.S. Pat. No. 8,170,995, which isincorporated by reference herein.

In order to further leverage the data stored in the informationmanagement system 100 to perform these and other tasks, one or morecomponents can be configured to scan data and/or associated metadata forclassification purposes to populate a database (or other data structure)of information (which can be referred to as a “data classificationdatabase” or a “metabase”). Depending on the embodiment, the dataclassification database(s) can be organized in a variety of differentways, including centralization, logical sub-divisions, and/or physicalsub-divisions. For instance, one or more centralized data classificationdatabases may be associated with different subsystems or tiers withinthe information management system 100. As an example, there may be afirst centralized metabase associated with the primary storage subsystem117 and a second centralized metabase associated with the secondarystorage subsystem 118. In other cases, there may be one or moremetabases associated with individual components. For instance, there maybe a dedicated metabase associated with some or all of the clientcomputing devices 102 and/or media agents 144. In some embodiments, adata classification database may reside as one or more data structureswithin management database 146, or may be otherwise associated withstorage manager 140.

In some cases, the metabase(s) may be included in separate database(s)and/or on separate storage device(s) from primary data 112 and/orsecondary copies 116, such that operations related to the metabase donot significantly impact performance on other components in theinformation management system 100. In other cases, the metabase(s) maybe stored along with primary data 112 and/or secondary copies 116. Filesor other data objects can be associated with identifiers (e.g., tagentries, etc.) in the media agent 144 (or other indices) to facilitatesearches of stored data objects. Among a number of other benefits, themetabase can also allow efficient, automatic identification of files orother data objects to associate with secondary copy or other informationmanagement operations (e.g., in lieu of scanning an entire file system).Examples of compatible metabases and data classification operations areprovided in U.S. Pat. Nos. 8,229,954 and 7,747,579, which areincorporated by reference herein.

Encryption Operations

The information management system 100 in some cases is configured toprocess data (e.g., files or other data objects, secondary copies 116,etc.), according to an appropriate encryption algorithm (e.g., Blowfish,Advanced Encryption Standard [AES], Triple Data Encryption Standard[3-DES], etc.) to limit access and provide data security in theinformation management system 100.

The information management system 100 in some cases encrypts the data atthe client level, such that the client computing devices 102 (e.g., thedata agents 142) encrypt the data prior to forwarding the data to othercomponents, e.g., before sending the data to media agents 144 during asecondary copy operation. In such cases, the client computing device 102may maintain or have access to an encryption key or passphrase fordecrypting the data upon restore. Encryption can also occur whencreating copies of secondary copies, e.g., when creating auxiliarycopies or archive copies. In yet further embodiments, the secondarystorage devices 108 can implement built-in, high performance hardwareencryption.

Management and Reporting Operations

Certain embodiments leverage the integrated, ubiquitous nature of theinformation management system 100 to provide useful system-widemanagement and reporting functions. Examples of some compatiblemanagement and reporting techniques are provided in U.S. Pat. No.7,343,453, which is incorporated by reference herein.

Operations management can generally include monitoring and managing thehealth and performance of information management system 100 by, withoutlimitation, performing error tracking, generating granularstorage/performance metrics (e.g., job success/failure information,deduplication efficiency, etc.), generating storage modeling and costinginformation, and the like.

As an example, a storage manager 140 or other component in theinformation management system 100 may analyze traffic patterns andsuggest or automatically route data via a particular route to e.g.,certain facilitate storage and minimize congestion. In some embodiments,the system can generate predictions relating to storage operations orstorage operation information. Such predictions described may be basedon a trending analysis that may be used to predict various networkoperations or use of network resources such as network traffic levels,storage media use, use of bandwidth of communication links, use of mediaagent components, etc. Further examples of traffic analysis, trendanalysis, prediction generation, and the like are described in U.S. Pat.No. 7,343,453, which is incorporated by reference herein.

In some configurations, a master storage manager 140 may track thestatus of a set of associated storage operation cells in a hierarchy ofinformation management cells, such as the status of jobs, systemcomponents, system resources, and other items, by communicating withstorage managers 140 (or other components) in the respective storageoperation cells. Moreover, the master storage manager 140 may track thestatus of its associated storage operation cells and associatedinformation management operations by receiving periodic status updatesfrom the storage managers 140 (or other components) in the respectivecells regarding jobs, system components, system resources, and otheritems. In some embodiments, a master storage manager 140 may storestatus information and other information regarding its associatedstorage operation cells and other system information in its index 150(or other location).

The master storage manager 140 or other component in the system may alsodetermine whether a storage-related criteria or other criteria issatisfied, and perform an action or trigger event (e.g., data migration)in response to the criteria being satisfied, such as where a storagethreshold is met for a particular volume, or where inadequate protectionexists for certain data. For instance, in some embodiments, the systemuses data from one or more storage operation cells to advise users ofrisks or indicates actions that can be used to mitigate or otherwiseminimize these risks, and in some embodiments, dynamically takes actionto mitigate or minimize these risks. For example, an informationmanagement policy may specify certain requirements (e.g., that a storagedevice should maintain a certain amount of free space, that secondarycopies should occur at a particular interval, that data should be agedand migrated to other storage after a particular period, that data on asecondary volume should always have a certain level of availability andbe able to be restored within a given time period, that data on asecondary volume may be mirrored or otherwise migrated to a specifiednumber of other volumes, etc.). If a risk condition or other criteria istriggered, the system can notify the user of these conditions and maysuggest (or automatically implement) an action to mitigate or otherwiseaddress the condition or minimize risk. For example, the system mayindicate that data from a primary copy 112 should be migrated to asecondary storage device 108 to free space on the primary storage device104. Examples of the use of risk factors and other triggering criteriaare described in U.S. Pat. No. 7,343,453, which is incorporated byreference herein.

In some embodiments, the system 100 may also determine whether a metricor other indication satisfies a particular storage criteria and, if so,perform an action. For example, as previously described, a storagepolicy or other definition might indicate that a storage manager 140should initiate a particular action if a storage metric or otherindication drops below or otherwise fails to satisfy specified criteriasuch as a threshold of data protection. Examples of such metrics aredescribed in U.S. Pat. No. 7,343,453, which is incorporated by referenceherein.

In some embodiments, risk factors may be quantified into certainmeasurable service or risk levels for ease of comprehension. Forexample, certain applications and associated data may be considered tobe more important by an enterprise than other data and services.Financial compliance data, for example, may be of greater importancethan marketing materials, etc. Network administrators may assignpriorities or “weights” to certain data or applications, correspondingto its importance (priority value). The level of compliance with thestorage operations specified for these applications may also be assigneda certain value. Thus, the health, impact and overall importance of aservice on an enterprise may be determined, for example, by measuringthe compliance value and calculating the product of the priority valueand the compliance value to determine the “service level” and comparingit to certain operational thresholds to determine if the operation isbeing performed within a specified data protection service level.Further examples of the service level determination are provided in U.S.Pat. No. 7,343,453, which is incorporated by reference herein.

The system 100 may additionally calculate data costing and dataavailability associated with information management operation cellsaccording to an embodiment of the invention. For instance, data receivedfrom the cell may be used in conjunction with hardware-relatedinformation and other information about network elements to generateindications of costs associated with storage of particular data in thesystem or the availability of particular data in the system. In general,components in the system are identified and associated information isobtained (dynamically or manually). Characteristics or metricsassociated with the network elements may be identified and associatedwith that component element for further use generating an indication ofstorage cost or data availability. Exemplary information generated couldinclude how fast a particular department is using up available storagespace, how long data would take to recover over a particular networkpathway from a particular secondary storage device, costs over time,etc. Moreover, in some embodiments, such information may be used todetermine or predict the overall cost associated with the storage ofcertain information. The cost associated with hosting a certainapplication may be based, at least in part, on the type of media onwhich the data resides. Storage devices may be assigned to a particularcost category which is indicative of the cost of storing information onthat device. Further examples of costing techniques are described inU.S. Pat. No. 7,343,453, which is incorporated by reference herein.

Any of the above types of information (e.g., information related totrending, predictions, job, cell or component status, risk, servicelevel, costing, etc.) can generally be provided to users via the userinterface 158 in a single, integrated view or console. The console maysupport a reporting capability that allows for the generation of avariety of reports, which may be tailored to a particular aspect ofinformation management. Report types may include: scheduling, eventmanagement, media management and data aging. Available reports may alsoinclude backup history, data aging history, auxiliary copy history, jobhistory, library and drive, media in library, restore history, andstorage policy. Such reports may be specified and created at a certainpoint in time as a network analysis, forecasting, or provisioning tool.Integrated reports may also be generated that illustrate storage andperformance metrics, risks and storage costing information. Moreover,users may create their own reports based on specific needs.

The integrated user interface 158 can include an option to show a“virtual view” of the system that graphically depicts the variouscomponents in the system using appropriate icons. As one example, theuser interface 158 may provide a graphical depiction of one or moreprimary storage devices 104, the secondary storage devices 108, dataagents 142 and/or media agents 144, and their relationship to oneanother in the information management system 100. The operationsmanagement functionality can facilitate planning and decision-making.For example, in some embodiments, a user may view the status of some orall jobs as well as the status of each component of the informationmanagement system 100. Users may then plan and make decisions based onthis data. For instance, a user may view high-level informationregarding storage operations for the information management system 100,such as job status, component status, resource status (e.g., networkpathways, etc.), and other information. The user may also drill down oruse other means to obtain more detailed information regarding aparticular component, job, or the like.

Further examples of some reporting techniques and associated interfacesproviding an integrated view of an information management system areprovided in U.S. Pat. No. 7,343,453, which is incorporated by referenceherein.

The information management system 100 can also be configured to performsystem-wide e-discovery operations in some embodiments. In general,e-discovery operations provide a unified collection and searchcapability for data in the system, such as data stored in the secondarystorage devices 108 (e.g., backups, archives, or other secondary copies116). For example, the information management system 100 may constructand maintain a virtual repository for data stored in the informationmanagement system 100 that is integrated across source applications 110,different storage device types, etc. According to some embodiments,e-discovery utilizes other techniques described herein, such as dataclassification and/or content indexing.

Information Management Policies

As indicated previously, an information management policy 148 caninclude a data structure or other information source that specifies aset of parameters (e.g., criteria and rules) associated with secondarycopy or other information management operations.

One type of information management policy 148 is a storage policy.According to certain embodiments, a storage policy generally comprises adata structure or other information source that defines (or includesinformation sufficient to determine) a set of preferences or othercriteria for performing information management operations. Storagepolicies can include one or more of the following items: (1) what datawill be associated with the storage policy; (2) a destination to whichthe data will be stored; (3) datapath information specifying how thedata will be communicated to the destination; (4) the type of storageoperation to be performed; and (5) retention information specifying howlong the data will be retained at the destination.

As an illustrative example, data associated with a storage policy can belogically organized into groups. In some cases, these logical groupingscan be referred to as “sub-clients”. A sub-client may represent staticor dynamic associations of portions of a data volume. Sub-clients mayrepresent mutually exclusive portions. Thus, in certain embodiments, aportion of data may be given a label and the association is stored as astatic entity in an index, database or other storage location.

Sub-clients may also be used as an effective administrative scheme oforganizing data according to data type, department within theenterprise, storage preferences, or the like. Depending on theconfiguration, sub-clients can correspond to files, folders, virtualmachines, databases, etc. In one exemplary scenario, an administratormay find it preferable to separate e-mail data from financial data usingtwo different sub-clients.

A storage policy can define where data is stored by specifying a targetor destination storage device (or group of storage devices). Forinstance, where the secondary storage device 108 includes a group ofdisk libraries, the storage policy may specify a particular disk libraryfor storing the sub-clients associated with the policy. As anotherexample, where the secondary storage devices 108 include one or moretape libraries, the storage policy may specify a particular tape libraryfor storing the sub-clients associated with the storage policy, and mayalso specify a drive pool and a tape pool defining a group of tapedrives and a group of tapes, respectively, for use in storing thesub-client data. While information in the storage policy can bestatically assigned in some cases, some or all of the information in thestorage policy can also be dynamically determined based on criteria,which can be set forth in the storage policy. For instance, based onsuch criteria, a particular destination storage device(s) (or otherparameter of the storage policy) may be determined based oncharacteristics associated with the data involved in a particularstorage operation, device availability (e.g., availability of asecondary storage device 108 or a media agent 144), network status andconditions (e.g., identified bottlenecks), user credentials, and thelike).

Datapath information can also be included in the storage policy. Forinstance, the storage policy may specify network pathways and componentsto utilize when moving the data to the destination storage device(s). Insome embodiments, the storage policy specifies one or more media agents144 for conveying data (e.g., one or more sub-clients) associated withthe storage policy between the source (e.g., one or more host clientcomputing devices 102) and destination (e.g., a particular targetsecondary storage device 108).

A storage policy can also specify the type(s) of operations associatedwith the storage policy, such as a backup, archive, snapshot, auxiliarycopy, or the like. Retention information can specify how long the datawill be kept, depending on organizational needs (e.g., a number of days,months, years, etc.)

The information management policies 148 may also include one or morescheduling policies specifying when and how often to perform operations.Scheduling information may specify with what frequency (e.g., hourly,weekly, daily, event-based, etc.) or under what triggering conditionssecondary copy or other information management operations will takeplace. Scheduling policies in some cases are associated with particularcomponents, such as particular logical groupings of data associated witha storage policy (e.g., a sub-client), client computing device 102, andthe like. In one configuration, a separate scheduling policy ismaintained for particular logical groupings of data on a clientcomputing device 102. The scheduling policy specifies that those logicalgroupings are to be moved to secondary storage devices 108 every houraccording to storage policies associated with the respectivesub-clients.

When adding a new client computing device 102, administrators canmanually configure information management policies 148 and/or othersettings, e.g., via the user interface 158. However, this can be aninvolved process resulting in delays, and it may be desirable to begindata protecting operations quickly.

Thus, in some embodiments, the information management system 100automatically applies a default configuration to client computing device102. As one example, when one or more data agent(s) 142 are installed onone or more client computing devices 102, the installation script mayregister the client computing device 102 with the storage manager 140,which in turn applies the default configuration to the new clientcomputing device 102. In this manner, data protection operations canbegin substantially immediately. The default configuration can include adefault storage policy, for example, and can specify any appropriateinformation sufficient to begin data protection operations. This caninclude a type of data protection operation, scheduling information, atarget secondary storage device 108, data path information (e.g., aparticular media agent 144), and the like.

Other types of information management policies 148 are possible. Forinstance, the information management policies 148 can also include oneor more audit or security policies. An audit policy is a set ofpreferences, rules and/or criteria that protect sensitive data in theinformation management system 100. For example, an audit policy maydefine “sensitive objects” as files or objects that contain particularkeywords (e.g., “confidential,” or “privileged”) and/or are associatedwith particular keywords (e.g., in metadata) or particular flags (e.g.,in metadata identifying a document or email as personal, confidential,etc.).

An audit policy may further specify rules for handling sensitiveobjects. As an example, an audit policy may require that a reviewerapprove the transfer of any sensitive objects to a cloud storage site,and that if approval is denied for a particular sensitive object, thesensitive object should be transferred to a local primary storage device104 instead. To facilitate this approval, the audit policy may furtherspecify how a secondary storage computing device 106 or other systemcomponent should notify a reviewer that a sensitive object is slated fortransfer.

In some implementations, the information management policies 148 mayinclude one or more provisioning policies. A provisioning policy caninclude a set of preferences, priorities, rules, and/or criteria thatspecify how client computing devices 102 (or groups thereof) may utilizesystem resources, such as available storage on cloud storage and/ornetwork bandwidth. A provisioning policy specifies, for example, dataquotas for particular client computing devices 102 (e.g., a number ofgigabytes that can be stored monthly, quarterly or annually). Thestorage manager 140 or other components may enforce the provisioningpolicy. For instance, the media agents 144 may enforce the policy whentransferring data to secondary storage devices 108. If a clientcomputing device 102 exceeds a quota, a budget for the client computingdevice 102 (or associated department) is adjusted accordingly or analert may trigger.

While the above types of information management policies 148 have beendescribed as separate policies, one or more of these can be generallycombined into a single information management policy 148. For instance,a storage policy may also include or otherwise be associated with one ormore scheduling, audit, or provisioning policies. Moreover, whilestorage policies are typically associated with moving and storing data,other policies may be associated with other types of informationmanagement operations. The following is a non-exhaustive list of itemsthe information management policies 148 may specify:

-   -   schedules or other timing information, e.g., specifying when        and/or how often to perform information management operations;    -   the type of copy 116 (e.g., type of secondary copy) and/or copy        format (e.g., snapshot, backup, archive, HSM, etc.);    -   a location or a class or quality of storage for storing        secondary copies 116 (e.g., one or more particular secondary        storage devices 108);    -   preferences regarding whether and how to encrypt, compress,        deduplicate, or otherwise modify or transform secondary copies        116;    -   which system components and/or network pathways (e.g., preferred        media agents 144) should be used to perform secondary storage        operations;    -   resource allocation between different computing devices or other        system components used in performing information management        operations (e.g., bandwidth allocation, available storage        capacity, etc.);    -   whether and how to synchronize or otherwise distribute files or        other data objects across multiple computing devices or hosted        services; and    -   retention information specifying the length of time primary data        112 and/or secondary copies 116 should be retained, e.g., in a        particular class or tier of storage devices, or within the        information management system 100.

Policies can additionally specify or depend on a variety of historicalor current criteria that may be used to determine which rules to applyto a particular data object, system component, or information managementoperation, such as:

-   -   frequency with which primary data 112 or a secondary copy 116 of        a data object or metadata has been or is predicted to be used,        accessed, or modified;    -   time-related factors (e.g., aging information such as time since        the creation or modification of a data object);    -   deduplication information (e.g., hashes, data blocks,        deduplication block size, deduplication efficiency or other        metrics);    -   an estimated or historic usage or cost associated with different        components (e.g., with secondary storage devices 108);    -   the identity of users, applications 110, client computing        devices 102 and/or other computing devices that created,        accessed, modified, or otherwise utilized primary data 112 or        secondary copies 116;    -   a relative sensitivity (e.g., confidentiality) of a data object,        e.g., as determined by its content and/or metadata;    -   the current or historical storage capacity of various storage        devices;    -   the current or historical network capacity of network pathways        connecting various components within the storage operation cell;    -   access control lists or other security information; and    -   the content of a particular data object (e.g., its textual        content) or of metadata associated with the data object.        Exemplary Storage Policy and Secondary Storage Operations

FIG. 1E shows a data flow data diagram depicting performance of storageoperations by an embodiment of an information management system 100,according to an exemplary storage policy 148A. The informationmanagement system 100 includes a storage manager 140, a client computingdevice 102 having a file system data agent 142A and an email data agent142B residing thereon, a primary storage device 104, two media agents144A, 144B, and two secondary storage devices 108A, 108B: a disk library108A and a tape library 108B. As shown, the primary storage device 104includes primary data 112A, 112B associated with a logical grouping ofdata associated with a file system) and a logical grouping of dataassociated with email data, respectively. Although for simplicity thelogical grouping of data associated with the file system is referred toas a file system sub-client, and the logical grouping of data associatedwith the email data is referred to as an email sub-client, thetechniques described with respect to FIG. 1E can be utilized inconjunction with data that is organized in a variety of other manners.

As indicated by the dashed box, the second media agent 144B and the tapelibrary 108B are “off-site”, and may therefore be remotely located fromthe other components in the information management system 100 (e.g., ina different city, office building, etc.). Indeed, “off-site” may referto a magnetic tape located in storage, which must be manually retrievedand loaded into a tape drive to be read. In this manner, informationstored on the tape library 108B may provide protection in the event of adisaster or other failure.

The file system sub-client and its associated primary data 112A incertain embodiments generally comprise information generated by the filesystem and/or operating system of the client computing device 102, andcan include, for example, file system data (e.g., regular files, filetables, mount points, etc.), operating system data (e.g., registries,event logs, etc.), and the like. The e-mail sub-client, on the otherhand, and its associated primary data 112B, include data generated by ane-mail client application operating on the client computing device 102,and can include mailbox information, folder information, emails,attachments, associated database information, and the like. As describedabove, the sub-clients can be logical containers, and the data includedin the corresponding primary data 112A, 112B may or may not be storedcontiguously.

The exemplary storage policy 148A includes backup copy preferences orrule set 160, disaster recovery copy preferences rule set 162, andcompliance copy preferences or rule set 164. The backup copy rule set160 specifies that it is associated with a file system sub-client 166and an email sub-client 168. Each of these sub-clients 166, 168 areassociated with the particular client computing device 102. The backupcopy rule set 160 further specifies that the backup operation will bewritten to the disk library 108A, and designates a particular mediaagent 144A to convey the data to the disk library 108A. Finally, thebackup copy rule set 160 specifies that backup copies created accordingto the rule set 160 are scheduled to be generated on an hourly basis andto be retained for 30 days. In some other embodiments, schedulinginformation is not included in the storage policy 148A, and is insteadspecified by a separate scheduling policy.

The disaster recovery copy rule set 162 is associated with the same twosub-clients 166, 168. However, the disaster recovery copy rule set 162is associated with the tape library 108B, unlike the backup copy ruleset 160. Moreover, the disaster recovery copy rule set 162 specifiesthat a different media agent 144B than the media agent 144A associatedwith the backup copy rule set 160 will be used to convey the data to thetape library 108B. As indicated, disaster recovery copies createdaccording to the rule set 162 will be retained for 60 days, and will begenerated on a daily basis. Disaster recovery copies generated accordingto the disaster recovery copy rule set 162 can provide protection in theevent of a disaster or other data-loss event that would affect thebackup copy 116A maintained on the disk library 108A.

The compliance copy rule set 164 is only associated with the emailsub-client 168, and not the file system sub-client 166. Compliancecopies generated according to the compliance copy rule set 164 willtherefore not include primary data 112A from the file system sub-client166. For instance, the organization may be under an obligation to storeand maintain copies of email data for a particular period of time (e.g.,10 years) to comply with state or federal regulations, while similarregulations do not apply to the file system data. The compliance copyrule set 164 is associated with the same tape library 108B and mediaagent 144B as the disaster recovery copy rule set 162, although adifferent storage device or media agent could be used in otherembodiments. Finally, the compliance copy rule set 164 specifies thatcopies generated under the compliance copy rule set 164 will be retainedfor 10 years, and will be generated on a quarterly basis.

At step 1, the storage manager 140 initiates a backup operationaccording to the backup copy rule set 160. For instance, a schedulingservice running on the storage manager 140 accesses schedulinginformation from the backup copy rule set 160 or a separate schedulingpolicy associated with the client computing device 102, and initiates abackup copy operation on an hourly basis. Thus, at the scheduled timeslot the storage manager 140 sends instructions to the client computingdevice 102 to begin the backup operation.

At step 2, the file system data agent 142A and the email data agent 142Bresiding on the client computing device 102 respond to the instructionsreceived from the storage manager 140 by accessing and processing theprimary data 112A, 112B involved in the copy operation from the primarystorage device 104. Because the operation is a backup copy operation,the data agent(s) 142A, 142B may format the data into a backup format orotherwise process the data.

At step 3, the client computing device 102 communicates the retrieved,processed data to the first media agent 144A, as directed by the storagemanager 140, according to the backup copy rule set 160. In some otherembodiments, the information management system 100 may implement aload-balancing, availability-based, or other appropriate algorithm toselect from the available set of media agents 144A, 144B. Regardless ofthe manner the media agent 144A is selected, the storage manager 140 mayfurther keep a record in the storage manager database 146 of theassociation between the selected media agent 144A and the clientcomputing device 102 and/or between the selected media agent 144A andthe backup copy 116A.

The target media agent 144A receives the data from the client computingdevice 102, and at step 4 conveys the data to the disk library 108A tocreate the backup copy 116A, again at the direction of the storagemanager 140 and according to the backup copy rule set 160. The secondarystorage device 108A can be selected in other ways. For instance, themedia agent 144A may have a dedicated association with a particularsecondary storage device(s), or the storage manager 140 or media agent144A may select from a plurality of secondary storage devices, e.g.,according to availability, using one of the techniques described in U.S.Pat. No. 7,246,207, which is incorporated by reference herein.

The media agent 144A can also update its index 153 to include dataand/or metadata related to the backup copy 116A, such as informationindicating where the backup copy 116A resides on the disk library 108A,data and metadata for cache retrieval, etc. After the 30 day retentionperiod expires, the storage manager 140 instructs the media agent 144Ato delete the backup copy 116A from the disk library 108A. The storagemanager 140 may similarly update its index 150 to include informationrelating to the storage operation, such as information relating to thetype of storage operation, a physical location associated with one ormore copies created by the storage operation, the time the storageoperation was performed, status information relating to the storageoperation, the components involved in the storage operation, and thelike. In some cases, the storage manager 140 may update its index 150 toinclude some or all of the information stored in the index 153 of themedia agent 144A.

At step 5, the storage manager 140 initiates the creation of a disasterrecovery copy 116B according to the disaster recovery copy rule set 162.For instance, at step 6, based on instructions received from the storagemanager 140 at step 5, the specified media agent 144B retrieves the mostrecent backup copy 116A from the disk library 108A.

At step 7, again at the direction of the storage manager 140 and asspecified in the disaster recovery copy rule set 162, the media agent144B uses the retrieved data to create a disaster recovery copy 116B onthe tape library 108B. In some cases, the disaster recovery copy 116B isa direct, mirror copy of the backup copy 116A, and remains in the backupformat. In other embodiments, the disaster recovery copy 116B may begenerated in some other manner, such as by using the primary data 112A,112B from the primary storage device 104 as source data. The disasterrecovery copy operation is initiated once a day and the disasterrecovery copies 116B are deleted after 60 days.

At step 8, the storage manager 140 initiates the creation of acompliance copy 116C, according to the compliance copy rule set 164. Forinstance, the storage manager 140 instructs the media agent 144B tocreate the compliance copy 116C on the tape library 108B at step 9, asspecified in the compliance copy rule set 164. In the example, thecompliance copy 116C is generated using the disaster recovery copy 116B.In other embodiments, the compliance copy 116C is instead generatedusing either the primary data 112B corresponding to the email sub-clientor using the backup copy 116A from the disk library 108A as source data.As specified, in the illustrated example, compliance copies 116C arecreated quarterly, and are deleted after ten years.

While not shown in FIG. 1E, at some later point in time, a restoreoperation can be initiated involving one or more of the secondary copies116A, 116B, 116C. As one example, a user may manually initiate a restoreof the backup copy 116A by interacting with the user interface 158 ofthe storage manager 140. The storage manager 140 then accesses data inits index 150 (and/or the respective storage policy 148A) associatedwith the selected backup copy 116A to identify the appropriate mediaagent 144A and/or secondary storage device 108A.

In other cases, a media agent may be selected for use in the restoreoperation based on a load balancing algorithm, an availability basedalgorithm, or other criteria. The selected media agent 144A retrievesthe data from the disk library 108A. For instance, the media agent 144Amay access its index 153 to identify a location of the backup copy 116Aon the disk library 108A, or may access location information residing onthe disk 108A itself.

When the backup copy 116A was recently created or accessed, the mediaagent 144A accesses a cached version of the backup copy 116A residing inthe index 153, without having to access the disk library 108A for someor all of the data. Once it has retrieved the backup copy 116A, themedia agent 144A communicates the data to the source client computingdevice 102. Upon receipt, the file system data agent 142A and the emaildata agent 142B may unpackage (e.g., restore from a backup format to thenative application format) the data in the backup copy 116A and restorethe unpackaged data to the primary storage device 104.

Exemplary Applications of Storage Policies

The storage manager 140 may permit a user to specify aspects of thestorage policy 148A. For example, the storage policy can be modified toinclude information governance policies to define how data should bemanaged in order to comply with a certain regulation or businessobjective. The various policies may be stored, for example, in thedatabase 146. An information governance policy may comprise aclassification policy, which is described herein. An informationgovernance policy may align with one or more compliance tasks that areimposed by regulations or business requirements. Examples of informationgovernance policies might include a Sarbanes-Oxley policy, a HIPAApolicy, an electronic discovery (E-Discovery) policy, and so on.

Information governance policies allow administrators to obtain differentperspectives on all of an organization's online and offline data,without the need for a dedicated data silo created solely for eachdifferent viewpoint. As described previously, the data storage systemsherein build a centralized index that reflects the contents of adistributed data set that spans numerous clients and storage devices,including both primary and secondary copies, and online and offlinecopies. An organization may apply multiple information governancepolicies in a top-down manner over that unified data set and indexingschema in order to permit an organization to view and manipulate thesingle data set through different lenses, each of which is adapted to aparticular compliance or business goal. Thus, for example, by applyingan E-discovery policy and a Sarbanes-Oxley policy, two different groupsof users in an organization can conduct two very different analyses ofthe same underlying physical set of data copies, which may bedistributed throughout the organization.

A classification policy defines a taxonomy of classification terms ortags relevant to a compliance task and/or business objective. Aclassification policy may also associate a defined tag with aclassification rule. A classification rule defines a particularcombination of data criteria, such as users who have created, accessedor modified a document or data object; file or application types;content or metadata keywords; clients or storage locations; dates ofdata creation and/or access; review status or other status within aworkflow (e.g., reviewed or un-reviewed); modification times or types ofmodifications; and/or any other data attributes. A classification rulemay also be defined using other classification tags in the taxonomy. Thevarious criteria used to define a classification rule may be combined inany suitable fashion, for example, via Boolean operators, to define acomplex classification rule. As an example, an E-discoveryclassification policy might define a classification tag “privileged”that is associated with documents or data objects that (1) were createdor modified by legal department staff, (2) were sent to or received fromoutside counsel via email, and/or (3) contain one of the followingkeywords: “privileged” or “attorney,” “counsel”, or other terms.

One specific type of classification tag, which may be added to an indexat the time of indexing, is an entity tag. An entity tag may be, forexample, any content that matches a defined data mask format. Examplesof entity tags might include, e.g., social security numbers (e.g., anynumerical content matching the formatting mask XXX-XX-XXXX), credit cardnumbers (e.g., content having a 13-16 digit string of numbers), SKUnumbers, product numbers, etc.

A user may define a classification policy by indicating criteria,parameters or descriptors of the policy via a graphical user interfacethat provides facilities to present information and receive input data,such as a form or page with fields to be filled in, pull-down menus orentries allowing one or more of several options to be selected, buttons,sliders, hypertext links or other known user interface tools forreceiving user input. For example, a user may define certain entitytags, such as a particular product number or project ID code that isrelevant in the organization.

In some implementations, the classification policy can be implementedusing cloud-based techniques. For example, the storage devices may becloud storage devices, and the storage manager 140 may execute cloudservice provider API over a network to classify data stored on cloudstorage devices.

Exemplary Secondary Copy Formatting

The formatting and structure of secondary copies 116 can vary, dependingon the embodiment. In some cases, secondary copies 116 are formatted asa series of logical data units or “chunks” (e.g., 512 MB, 1 GB, 2 GB, 4GB, or 8 GB chunks). This can facilitate efficient communication andwriting to secondary storage devices 108, e.g., according to resourceavailability. For example, a single secondary copy 116 may be written ona chunk-by-chunk basis to a single secondary storage device 108 oracross multiple secondary storage devices 108. In some cases, users canselect different chunk sizes, e.g., to improve throughput to tapestorage devices.

Generally, each chunk can include a header and a payload. The payloadcan include files (or other data units) or subsets thereof included inthe chunk, whereas the chunk header generally includes metadata relatingto the chunk, some or all of which may be derived from the payload. Forexample, during a secondary copy operation, the media agent 144, storagemanager 140, or other component may divide the associated files intochunks and generate headers for each chunk by processing the constituentfiles.

The headers can include a variety of information such as fileidentifier(s), volume(s), offset(s), or other information associatedwith the payload data items, a chunk sequence number, etc. Importantly,in addition to being stored with the secondary copy 116 on the secondarystorage device 108, the chunk headers can also be stored to the index153 of the associated media agent(s) 144 and/or the index 150. This isuseful in some cases for providing faster processing of secondary copies116 during restores or other operations. In some cases, once a chunk issuccessfully transferred to a secondary storage device 108, thesecondary storage device 108 returns an indication of receipt, e.g., tothe media agent 144 and/or storage manager 140, which may update theirrespective indexes 153, 150 accordingly. During restore, chunks may beprocessed (e.g., by the media agent 144) according to the information inthe chunk header to reassemble the files.

Data can also be communicated within the information management system100 in data channels that connect the client computing devices 102 tothe secondary storage devices 108. These data channels can be referredto as “data streams”, and multiple data streams can be employed toparallelize an information management operation, improving data transferrate, among providing other advantages. Example data formattingtechniques including techniques involving data streaming, chunking, andthe use of other data structures in creating copies (e.g., secondarycopies) are described in U.S. Pat. Nos. 7,315,923 and 8,156,086, and8,578,120, each of which is incorporated by reference herein.

FIGS. 1F and 1G are diagrams of example data streams 170 and 171,respectively, which may be employed for performing data storageoperations. Referring to FIG. 1F, the data agent 142 forms the datastream 170 from the data associated with a client computing device 102(e.g., primary data 112). The data stream 170 is composed of multiplepairs of stream header 172 and stream data (or stream payload) 174. Thedata streams 170 and 171 shown in the illustrated example are for asingle-instanced storage operation, and a stream payload 174 thereforemay include both single-instance (“SI”) data and/or non-SI data. Astream header 172 includes metadata about the stream payload 174. Thismetadata may include, for example, a length of the stream payload 174,an indication of whether the stream payload 174 is encrypted, anindication of whether the stream payload 174 is compressed, an archivefile identifier (ID), an indication of whether the stream payload 174 issingle instanceable, and an indication of whether the stream payload 174is a start of a block of data.

Referring to FIG. 1G, the data stream 171 has the stream header 172 andstream payload 174 aligned into multiple data blocks. In this example,the data blocks are of size 64 KB. The first two stream header 172 andstream payload 174 pairs comprise a first data block of size 64 KB. Thefirst stream header 172 indicates that the length of the succeedingstream payload 174 is 63 KB and that it is the start of a data block.The next stream header 172 indicates that the succeeding stream payload174 has a length of 1 KB and that it is not the start of a new datablock. Immediately following stream payload 174 is a pair comprising anidentifier header 176 and identifier data 178. The identifier header 176includes an indication that the succeeding identifier data 178 includesthe identifier for the immediately previous data block. The identifierdata 178 includes the identifier that the data agent 142 generated forthe data block. The data stream 171 also includes other stream header172 and stream payload 174 pairs, which may be for SI data and/or fornon-SI data.

FIG. 1H is a diagram illustrating the data structures 180 that may beused to store blocks of SI data and non-SI data on the storage device(e.g., secondary storage device 108). According to certain embodiments,the data structures 180 do not form part of a native file system of thestorage device. The data structures 180 include one or more volumefolders 182, one or more chunk folders 184/185 within the volume folder182, and multiple files within the chunk folder 184. Each chunk folder184/185 includes a metadata file 186/187, a metadata index file 188/189,one or more container files 190/191/193, and a container index file192/194. The metadata file 186/187 stores non-SI data blocks as well aslinks to SI data blocks stored in container files. The metadata indexfile 188/189 stores an index to the data in the metadata file 186/187.The container files 190/191/193 store SI data blocks. The containerindex file 192/194 stores an index to the container files 190/191/193.Among other things, the container index file 192/194 stores anindication of whether a corresponding block in a container file190/191/193 is referred to by a link in a metadata file 186/187. Forexample, data block B2 in the container file 190 is referred to by alink in the metadata file 187 in the chunk folder 185. Accordingly, thecorresponding index entry in the container index file 192 indicates thatthe data block B2 in the container file 190 is referred to. As anotherexample, data block B1 in the container file 191 is referred to by alink in the metadata file 187, and so the corresponding index entry inthe container index file 192 indicates that this data block is referredto.

As an example, the data structures 180 illustrated in FIG. 1H may havebeen created as a result of two storage operations involving two clientcomputing devices 102. For example, a first storage operation on a firstclient computing device 102 could result in the creation of the firstchunk folder 184, and a second storage operation on a second clientcomputing device 102 could result in the creation of the second chunkfolder 185. The container files 190/191 in the first chunk folder 184would contain the blocks of SI data of the first client computing device102. If the two client computing devices 102 have substantially similardata, the second storage operation on the data of the second clientcomputing device 102 would result in the media agent 144 storingprimarily links to the data blocks of the first client computing device102 that are already stored in the container files 190/191. Accordingly,while a first storage operation may result in storing nearly all of thedata subject to the storage operation, subsequent storage operationsinvolving similar data may result in substantial data storage spacesavings, because links to already stored data blocks can be storedinstead of additional instances of data blocks.

If the operating system of the secondary storage computing device 106 onwhich the media agent 144 resides supports sparse files, then when themedia agent 144 creates container files 190/191/193, it can create themas sparse files. As previously described, a sparse file is type of filethat may include empty space (e.g., a sparse file may have real datawithin it, such as at the beginning of the file and/or at the end of thefile, but may also have empty space in it that is not storing actualdata, such as a contiguous range of bytes all having a value of zero).Having the container files 190/191/193 be sparse files allows the mediaagent 144 to free up space in the container files 190/191/193 whenblocks of data in the container files 190/191/193 no longer need to bestored on the storage devices. In some examples, the media agent 144creates a new container file 190/191/193 when a container file190/191/193 either includes 100 blocks of data or when the size of thecontainer file 190 exceeds 50 MB. In other examples, the media agent 144creates a new container file 190/191/193 when a container file190/191/193 satisfies other criteria (e.g., it contains fromapproximately 100 to approximately 1000 blocks or when its size exceedsapproximately 50 MB to 1 GB).

In some cases, a file on which a storage operation is performed maycomprise a large number of data blocks. For example, a 100 MB file maybe comprised in 400 data blocks of size 256 KB. If such a file is to bestored, its data blocks may span more than one container file, or evenmore than one chunk folder. As another example, a database file of 20 GBmay comprise over 40,000 data blocks of size 512 KB. If such a databasefile is to be stored, its data blocks will likely span multiplecontainer files, multiple chunk folders, and potentially multiple volumefolders. As described in detail herein, restoring such files may thusrequiring accessing multiple container files, chunk folders, and/orvolume folders to obtain the requisite data blocks.

Snapshot Management System

FIG. 2 illustrates an example information management system 200 forsnapshot management according to one or more embodiments disclosedherein. Snapshots can be point-in-time images of production data, or ofcopies of production data, including replicated copies, for example.Snapshots can also include system state data, application state data,file system data, and other types of information. As just one example,application state and/or system data can be used to recover from a crashto an application state that existed prior to a crash. Wherever taking asnapshot of data is described in this disclosure, it should beunderstood that the data can include production data, system state data,application state data, file system data, or any other relevant dataand/or information. Although a variety of snapshot techniques arecompatible with the embodiments described herein, in some embodiments,the snapshots can be created by maintaining pointers to unchanged dataand copying changed data (e.g., blocks), using a copy-on-writemethodology, for example. The system 200 of FIG. 2 includes a storagemanager 240, one or more source systems 202, 203 (e.g., client system),and at least one destination storage system or destination system 216and storage array or one or more storage devices 208. In general, thecomponents shown in FIG. 2 may be similar to corresponding componentsshown in certain of FIGS. 1A-1H. For instance, one or more of thestorage manager 240, source system 202, data agent(s) 242, anddestination system 216 may be similar to the storage manager 140, client102, data agent(s) 142, and primary and/or secondary storage device(s),respectively, of certain of FIGS. 1A-1H.

In certain embodiments, the system 200 includes a storage manager 240,which may include one or more of the following modules or components: avolume replication table, a storage manager index cache, a client, aninformation store, a data agent, a media agent, a media agent indexcache, and a storage device.

The source system 202 may include one or more applications 210, one ormore data agents 242, and a snapshot manager 224 executing thereon. Theapplications 210 can include software applications executing on thesource system 202 and may generate and modify production data. As just afew examples, the software applications 210 may include databaseapplications, server software, virtual machine managers, operatingsystems, file system management software, and other types ofapplications.

The source system 202 can include a data store or source storage 204 forstoring the production data generated by the applications 210. Thesource storage 204 may include any type of physical media capable ofstoring electronic data. For example, the source storage 204 maycomprise magnetic storage, such as a disk drive, or other type of massstorage. In certain embodiments, the source storage 204 may be internaland/or external to (e.g., remote to) one or more other components of thesource system 202. In yet other embodiments, the source storage 204 caninclude a network-attached storage (NAS) or the like. In certainembodiments, the source storage 204 includes relatively fast accesstimes as compared to tape or other relatively slower or less expensivemedia. For instance, the source storage can include hard disk drives(HDD's) including spinning media or solid state drives (SSD's) includingsolid-state storage, such as flash-based or DRAM-based SSD's.

In certain embodiments, the data agent(s) 242 provide an interface to asource data store 204 to execute copies, snapshots, archiving,migration, recovery and other storage operations on data, for example,in conjunction with one or more media agents. In certain embodiments, asource system 202 runs a number of data agents 242, wherein each dataagent is configured to interface with data generated by or from one ormore applications 210. For example, a first data agent may be configuredto interface with Microsoft Exchange data and a second data agent tointerface with Oracle database data. As is explained in greater detailherein, a data agent 242 may be in communication with one or more mediaagents to effect the distributed storage of snapshots on one or morestorage devices that are remote from the information store that is thesource of the snapshot.

The storage manager 240 may communicate with data and/or media agents tocontrol and manage snapshot creation, migration, recovery and otherstorage operations. According to one embodiment, the storage manager 240maintains data in a storage manager index cache that instructs a givendata agent 242 to work in conjunction with a specific media agent tostore snapshots on one or more storage devices 208. In certainembodiments, a snapshot is spread over multiple storage devices. Incertain embodiments, metadata associated with one or more snapshots isstored in the media agent(s) 252, whereas the storage array 208 providesstorage for the snapshots themselves. Storage may be provisioned fromthe destination storage array 208 to the source system 202. In certainembodiments, application agents of the source system 202 providerequests to the media agent(s) 252, wherein the media agent(s)communicates requests to the storage array 208 for snapshot creation.

The snapshot manager 224 can be a software module that is generallyconfigured to manage interaction with the destination system 216 tocarry out snapshot operations. The snapshot operations can include,without limitation, snapshot creation, mounting, unmounting, deletionand reversion. The components of the snapshot manager 224 in someembodiments work together to gather and/or package the appropriate dataand metadata related to the requested snapshot operation fortransmission to the destination system 216. In certain embodiments, thesnapshot management layer or snapshot manager 224 or portions thereofare implemented on a proxy system (not shown) that is separate from thesource system 202, instead of, or in addition to being implemented onthe source system 202. The proxy system can therefore be configured toperform some or all of the snapshot management processing, therebyalleviating the associated burden from the source system 202 andimproving performance of the source system 202.

The snapshot manager 224 may utilize mapping information 225 to trackmultiple snapshots across multiple storage devices. For example, thesystem may, as directed by an information management policy or a user,store a first snapshot on a first storage device, such as a tape driveor library, and then store subsequent snapshots containing only thechanged cluster(s) on a second storage device, such as an optical driveor library. Alternatively, instructions may be stored within systemcomponents, such as the storage manager 240 or media agent 252,directing the storage device(s) 208 used to store snapshots.

The mapping information 225 may provide mapping data for locating and/oridentifying data in the snapshot associated with one or more particularapplications and/or agents. Furthermore, the mapping information 225 mayindicate the number and/or type of applications associated with thesnapshot data. In certain embodiments, the mapping information ismaintained by one or more of the requesting applications associated withthe snapshot. For example, a first application associated with thesnapshot may initiate population of the mapping information 225 byproviding information related to itself, wherein subsequent applicationsassociated with the snapshot may provide further data. In certainembodiments, the mapping information 225 is used to locate relevant datafor restoration of data associated with one or more of the applications.

In certain embodiments, certain storage devices of the system areconfigured to create and/or store snapshot copies of production datathat is generated by applications running on the source system 202, suchas the production data stored in the source storage 204. For example,destination storage devices can be capable of performing hardware-basedsnapshots (e.g., storage array-based hardware snapshots).

The snapshot manager 224 may manage the creation of a snapshot in thecorresponding storage array 208. In some embodiments, the snapshotmanager 224 is a software module executing on the source system 202, oris implemented in hardware/software on the destination system 216.Furthermore, in certain embodiments, the snapshot manager 224 is acomponent of the storage manager 240.

The data agents 242 may generally manage the movement of the productiondata from the applications to the source storage 204 and/or otherlocations in the storage system 200. In some embodiments, the dataagents 242 manage movement of the production data to the storage array208, either directly, or indirectly (e.g., from the source storage 204),depending on the embodiment. The data agents 242 can also be responsiblefor backing up, archiving, migrating or otherwise creating copies ofproduction data on secondary storage, either directly, or via one ormore media agents.

Each data agent 242 may be application-specific and associated with acorresponding application, such as any of the applications or types ofapplications discussed herein. For example, without limitation, a dataagent 242 may be associated with one or more of the following: DB2,Informix, Microsoft Exchange, Microsoft Hyper-V, Microsoft SharePoint,Microsoft SQL, Oracle, SAP, and Microsoft Windows, Linux and Unix filesystems. In certain embodiments, the data agents 242 may be generic,where each data agent is capable of handling two or more data types,such as data generated by more than one applications. The data agents insome embodiments process data to provide application-consistent storageof production data. In some embodiments, the data agents 242 are incommunication with the snapshot manager 224 and are responsible fordirecting data and metadata transfer between the snapshot manager 224and the source storage 204 during snapshot operations.

The system 200 includes a destination system 216 where snapshots and/orbackup copies may be stored. The destination system may include one ormore media agents 252, an index cache 253, and a storage array 208comprising media on which snapshots and/or backup copies may be stored.In certain embodiments, the media agent(s) and/or storage array 208 maybe separate from the destination system 216. The destination system 216may include an index, or index cache 253, which may include datagenerated during secondary copy operations and other storage orinformation management operations. The index cache 253 can provide themedia agent(s) 252 with a fast and efficient mechanism for locatingsnapshots located in the storage array 208, or other data stored in thestorage array 208. In certain embodiments, the index cache 253 includesmetadata or other information relating to data stored in the storagearray 208. Such metadata may include, for example, a path to thesnapshots 209 stored in the storage array 208, when the snapshots werecreated or modified, etc. The index cache 253 may, therefore, includemetadata associated with the snapshots that is readily available for usein storage operations and other activities without having to be firstretrieved from the storage array 208. In certain embodiments, some orall of the data in the index cache 253 may instead or additionally bestored along with the snapshots 209 in the storage array 208.

The media agent 252 may receive snapshots, possibly including thechanged data that is tracked by the snapshot, from one or more dataagents 242 and determine one or more storage arrays 208 to which thesnapshot should be written. According to one embodiment, the media agent252 applies load-balancing algorithms to select a storage array 208 towhich to write the snapshot. Alternatively, the snapshots may beprovided directly to the storage array 208 by the source system 202,such as by one or more data agents 242.

In certain embodiments, the storage manager 240 may instruct the mediaagent 252 as to which storage array 208 the snapshot should be written.In this manner, snapshots from given source storage 204 may be writtento one or more storage arrays 208, improving data availability forrestoration purposes in the event that the source storage fails. Eitherthe media agent 252 or the storage manager 240 may record the storagedevice on which the snapshot is written in the mapping information 225,thereby allowing the snapshot to be located when required for restoringthe source storage 204.

The index cache 253 may be configured to store index data the systemgenerates during snapshot, migration, and restore operations. Forexample, storage operations for Microsoft Exchange data generateapplication specific index data regarding the substantive Exchange data.Similarly, other applications may be capable of generating applicationspecific data during a snapshot. Such data may generally be described asmetadata. A media agent index cache may track data that includes, forexample, information regarding the location of stored data on a givenvolume. Index data provides the system with an efficient mechanism forlocating user files during storage operations such as copying,performing snapshots and recovery. In certain embodiments, the indexdata may be stored with the snapshot that is backed up to thedestination storage 208, and the media agent that controls the storageoperation may also write an additional copy of the index data to itsmedia agent index cache.

The destination storage 208 may include any type of physical mediacapable of storing electronic data. For example, the destination storage208 may comprise magnetic storage, such as a disk or a tape drive, orother type of mass storage. In certain embodiments, the destinationstorage 208 may be internal and/or external to (e.g., remote to) one ormore other components of the destination system 216. In yet otherembodiments, the destination storage 208 can include a NAS or the like.In certain embodiments, the destination storage 208 includes relativelyfast access times as compared to tape or other relatively slower or lessexpensive media. For instance, the destination storage can include harddisk drives (HDD's) including spinning media or solid state drives(SSD's) including solid-state storage, such as flash-based or DRAM-basedSSD's. In certain embodiments, the destination system 216 includes oneor more separate computing devices (not shown). For instance, wherereplication is used (e.g., continuous data replication (CDR)), thedestination system 216 may include a separate computing device incommunication with the destination system 216 and including areplication module configured to manage replication of the data storedin the source storage 204.

Data Storage Allocation for Snapshots

Certain embodiments disclosed herein provide a system requiring areduced number of snapshots, wherein a global snapshot is taken andvirtually separated into relevant portions for particular clients andapplication. An information management system may include one or moredestination and/or source storage devices. FIG. 3 illustrates an exampledata storage device comprising one or more volumes of client productiondata of which snapshots may be taken in accordance with one or moreembodiments disclosed herein. In an information management system, astorage device 330 may be partitioned into one or more logical volumesor other independently accessible portions. In certain embodiments, thestorage device 330 may include one or more Logical Unit Numbers (LUNs)331 (e.g., hardware disks or spindles), each of which stores one or moresuch volumes (e.g., production data associated with a client, such asClient A). A LUN may comprise an externally addressable entity within atarget device that implements an SCSI device model. Each of the clientvolumes may be a component of a storage stack, which may include filesystems, volume managers, device drivers, storage devices, and/or othercomponents that operate together to provide access to the storage.Client volumes and backup images stored therein may be used for backupoperations, snapshot operations, and restore operations, in such caseswhere the storage device 330 also serves as a secondary storage devicein addition to being primary storage.

In certain systems, multiple applications and/or clients may share asingle LUN for data storage. For example, multiple databases (e.g., DB1,DB2, DB3) may be stored on the LUN 331 in association with one or moreclient volumes 335. Furthermore, the LUN 331 may include data generatedby both database applications and file system data applications 311, asshown. In certain systems or embodiments, when a snapshot is performedfor a particular application/database (e.g., for DB1 associated withClient A), a snapshot may be taken of the entire LUN 331 with which theapplication is associated. The relevant portions of the snapshot may besubsequently identified and stored in association with the requestingapplication. However, remaining portions of the snapshot may then bediscarded, introducing operational inefficiencies into the snapshotsystem. Certain embodiments disclosed herein provide systems and methodsfor reusing global snapshots for multiple applications and/or clients,thereby improving operational efficiency.

An Exemplary Information Management System for Implementing SingleSnapshot for Multiple

Applications

FIG. 4 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary information management system 400configured to implement and generate a single snapshot for multipleapplications, according to certain embodiments. As illustrated, theexemplary information management system 400 includes a storage manager410, one or more clients 420, one or more information stores or primarystorage devices 430, one or more data agents 440, one or more snapshotmanagers 450, one or more applications 460, one or more media agents470, and one or more secondary storage devices 480. The system 400 andcorresponding components of FIG. 4 may be similar to or the same as thesystem 100, 200 and similarly named (though not necessarily similarlynumbered) components of FIGS. 1D and 2.

The components of FIG. 4 may be similar to the components in FIG. 2. Forexample, the snapshot manager 450 may be similar to the snapshot manager224 in FIG. 2. The clients 420 can be similar to the source systems 202in FIG. 2. The information store or primary storage device(s) 430 or thesecondary storage device(s) 480 may be similar to the storage array 208and/or the destination system 216 in FIG. 2.

Moreover, depending on the embodiment, the system 400 of FIG. 4 mayadditionally include any of the other components shown in FIGS. 1D and 2that are not specifically shown in FIG. 4. The system 400 may includeone or more of each component. All components of the system 400 can bein direct communication with each other or communicate indirectly viathe client 420, the storage manager 410, the media agent 470, or thelike. In certain embodiments, some of the components in FIG. 4 shown asseparate components can reside on a single computing device, or viceversa. For example, the snapshot manager 450 can be on the storagemanager 410, the client 420, or on a separate computing device.

In certain embodiments, for example, described with respect to FIGS.4-7, the snapshot manager 450 may direct the timing of the singlesnapshot (e.g., according to a storage policy). In other embodiments,for example, as described with respect to FIGS. 2-3 and 8-10, thesnapshot manager 224 may play a more passive role and obtain the singlesnapshot based on snapshot requests from the applications 210. Forexample, the snapshot manager 224 can group snapshot requests frommultiple applications 210 based on time of receipt (e.g., receivedwithin a time window) and obtain a single snapshot.

A snapshot may refer to the state of a system at a particular point intime. A snapshot may be a read-only copy of data frozen at a point intime. The snapshot can be an actual copy of the state of a system or mayinclude a set of pointers to the data. Snapshots can be createdefficiently; the time it takes to create a snapshot does not increasewith the size of the data. In some cases, after the initial snapshot istaken of a data set, subsequent snapshots use pointers to reference theinitial snapshot and copy only changed data. Pointer-based snapshots mayrequire much less disk space than full copy snapshots.

Data associated with multiple applications may be stored on the samelogical volume (e.g., LUN). In general, when an application requests asnapshot of data associated with the application, the snapshot of theentire volume is taken, although the data of interest may only be thedata for the requesting application. Accordingly, the system 400 cancoordinate snapshot operations such that a single snapshot can be takenfor multiple applications whose data is residing on the same volume. Forexample, the system 400 can take a single snapshot for applications thathave a similar snapshot frequency. The applications associated with thedata stored on a particular volume can each be quiesced or placed in aconsistent state, and the system 400 can take a single snapshot of thevolume. Then, the system 400 can create metadata relating to whichportion of the snapshot is associated with which application.

In this manner, the system 400 can reduce the number of snapshots to betaken. In some embodiments, the organization associated with the system400 may license the snapshot technology and may be allowed a limitednumber of snapshots for a certain amount of fees. Being able to reducethe number of snapshots taken can lead to savings in costs as well asresources.

At data flow step 1, the snapshot manager 450 inquires whetherapplications 460 are quiesced. The snapshot manager 450 can reside onthe storage manager 410 or the client 420, depending on the embodiment.The snapshot manager 450 may coordinate and/or manage snapshotoperations, including taking a single snapshot for multipleapplications. The snapshot manager 450 may be similar to the snapshotmanager 224 in FIG. 2.

The system 400 can include one or more clients or client computingdevices 420. The clients 420 can be similar to the source systems 202 inFIG. 2. One or more applications 460 may be installed on a client 420.The applications 460 installed can be the same across all clients 420 orvary depending on the client 420 (e.g., based on each client 420, basedon the group the client 420 belongs to, etc.). Some examples ofapplications 460 include database applications, email applications, wordprocessing applications, operating systems, virtual machines, etc.

The data associated with the applications 460 may be stored on theinformation store or primary storage device 430. The information store430 can be shared by multiple clients 420. In some embodiments, theinformation store 430 is organized as one or more LUNs including one ormore volumes, as described in FIG. 3. For example, the information store430 can be similar to the storage device 330 in FIG. 3. The same LUN orvolume can include data for multiple applications. In one embodiment,the information store 430 includes both application data and file systemdata.

An application 460 may be associated with a particular data agent 440.For example, Oracle may have a data agent 440 associated with it, andExchange may have a data agent 440 associated with it. There can also bea data agent 440 for a file system (e.g., for Windows, Linux, Unix,etc.). A data agent 440 can manage and process a particular type ofdata, for example, in connection with various storage operations. Forexample, a data agent 440 may know how the data of an application 460 isstructured and what operations are supported by the application 460. Thedata agent 440 may have knowledge of the format of the data of theapplication 460 and/or the directory structure or hierarchy of theapplication 460 and/or the file system. Data agents 440 may be installedon the clients 420 that have the corresponding or associatedapplications 460 and/or file systems installed.

In an illustrative example of FIG. 4, Data Agent 1 440 a is associatedwith Application 1 460 a; Data Agent 2 440 b is associated withApplication 2 460 b; and Data Agent 3 440 c is associated withApplication 3 460 c. Application 1 460 a is installed on both Client 1420 a and Client 2 420 b, and Application 2 460 b and 3 460 c areinstalled on Client 1 420 a and Client 2 420 b, respectively. Thecorrespondence between a data agent 440 and an application 460 may beone-to-one, one-to-many, many-to-one, etc. In the example of FIG. 4, onedata agent 440 is associated with one application 460. In someembodiments, one data agent 440 manages more than one type ofapplication 460.

In the example of FIG. 4, Client 1 420 a and Client 2 420 b share aninformation store 430. Client 1 420 a has Application 1 460 a andApplication 2 460 b installed. Client 2 420 b has Application 1 460 aand Application 3 460 c installed. Both Client 1 420 a and Client 2 420b use a specific operating system or file system (e.g., Windows). Thedata generated by Application 1 460 a, Application 2 460 b, andApplication 3 460 c are stored in the information store 430. The datarelating to the file systems of Client 1 420 a and Client 2 420 b isalso stored in the information store 430. In certain embodiments, thedata for a particular client 420 is stored in a separate volume 435 orLUN 431. For instance, data for Client 1 420 a is stored in one volume435 a (Volume 1) in a LUN 431 a (LUN 1), and data for Client 2 420 b isstored in another volume 435 b (Volume 2) in another LUN 431 b (LUN 2).In other embodiments, a LUN 431 can include multiple volumes 435, or avolume 435 can include multiple LUNs 431.

The snapshot manager 450 may obtain a snapshot of a specific volume 435or LUN 431 in the information store 430 that contains data for multipleapplications 460. The snapshot manager 450 may not directly take asnapshot, but may coordinate a snapshot operation with variouscomponents of the system 400, such as the media agent 470. As explainedabove, a single snapshot can be taken for multiple applications 460. Forinstance, with respect to Client 1 420 a, the snapshot manager 450 cantake a snapshot of data associated with Application 1 460 a and dataassociated with Application 2 460 b by coordinating a single snapshotfor Volume 1 435 a or LUN 1 431 a when both Application 1 460 a andApplication 2 460 b are quiesced. Similarly, with respect to Client 2420 b, the snapshot manager 450 can take a snapshot of data associatedwith Application 1 460 a and data associated with Application 3 460 c bycoordinating a single snapshot for Volume 2 435 b or LUN 2 431 b whenboth Application 1 460 a and Application 3 460 c are quiesced. Thesnapshot according to the illustrative embodiment is accompanied byapplication-specific indexing as explained in further detail below.

In some embodiments, the snapshot manager 450 coordinates taking asingle snapshot of a virtual machine (VM) that has multiple applications460 installed. The snapshot manager 450 instructs various components ofthe system 400 to obtain a single snapshot of all data for the VM, whichincludes data for multiple applications.

The snapshot manager 450 can check whether applications 460 whose datais stored on a volume are quiesced or in consistent states. A“consistent state” can refer to a state of an application in which theoperations are temporarily stopped and/or suspended to allow a snapshotto be taken of the application. Data of an application 460 can berecovered from a consistent state. A consistent state may also bereferred to as a good known state. The snapshot manager 450 maydetermine which applications 460 should be quiesced. The snapshotmanager 450 can detect the applications 460 that are running orinstalled on a client 420 by determining which types of data agents 440are running or installed on the client 420. By determining the dataagents 440 on the client 420, the snapshot manager 450 may determinewhat types of application data are stored in the information store 430.The snapshot manager 450 may find out whether the applications 460 arein consistent states by inquiring with the respective data agents 440associated with the applications 460. Each data agent 440 cancommunicate with the application 460 to determine whether theapplication 460 is in a consistent state and ready for a snapshotoperation to proceed.

Snapshot operations may run according to a schedule, at user request,based on a storage policy such as any of the storage policies describedherein, based on certain events, etc. A schedule may be based on thepassage of a pre-determined amount of time, such as on a regular basis(e.g., after a particular time interval, such as a certain number ofhours or days), or on an intermittent basis. Snapshot operations mayalso be event-based and may be triggered by certain events (e.g., aftera new version of software is installed on a component of the system400). Snapshot operations can be implemented as one or more storagepolicies, and the storage manager 410 may manage such storage policies.

The snapshot manager 450 may coordinate snapshots according to one ormore storage policies. The frequency for taking snapshots may vary,e.g., depending on the application 460. For example, the snapshot forExchange may need to be taken every 6 hours, and the snapshot for SQLmay need to be taken every 3 hours, as defined by one or more storagepolicies associated with the applications (e.g., by a single storagepolicy associated with both applications 460 or by individual storagepolicies associated with each application 460). The applications 460that have a similar frequency for snapshots can be scheduled or groupedtogether in one snapshot storage policy. For instance, the storagemanager 410 or the snapshot manager 450 can implement a snapshot storagepolicy for some applications 460 that have a 3-hour frequency, andimplement another snapshot storage policy for other applications 460that have a 6-hour frequency. In some embodiments, applications 460having different snapshot frequencies can be implemented within a singlestorage policy. For instance, a single storage policy can include asub-plan for a first group of applications 460 having one frequency andanother sub-plan for a second group of applications 460 having adifferent frequency. A snapshot storage policy may also specify aretention period for storing the snapshot data. Each application 460 mayhave a different retention period for the snapshot data. For example,Exchange snapshot data is stored for 4 years; virtual machine snapshotdata is stored for 30 days; and SQL snapshot data is stored for 10+years. As with snapshot frequency, in such cases, the storage manager410 or snapshot manager 450 can implement one or more snapshot storagepolicies for applications 460 having similar retention periods. Forinstance, the storage manager 410 or snapshot manager 450 can implementa snapshot storage policy for some applications 460 that have a firstretention period and another snapshot storage policy for otherapplications that have a different retention period. Or, a singlestorage policy can include a sub-plan for a first group of applications460 having one retention period and another sub-plan for a second groupof applications 460 having a different retention period. Further detailsrelating to policies are explained above, for example, in connectionwith FIG. 1E.

At data flow step 2, the data agents 440 quiesce associated applications460. When a data agent 440 receives an inquiry from the snapshot manager450, the data agent 440 can check whether its associated application 460is in a consistent state. If the application 460 is not in a consistentstate, the data agent 440 can engage appropriate writers or scripts toinstruct the application 460 to enter a consistent state. Theapplications 460 can take appropriate steps to come to a state whereeach is ready for a snapshot operation to proceed.

In some embodiments, the data agent 440 that first receives an inquiryfrom the snapshot manager 450 acts as a specialized data agent 440 andcoordinates tasks relating to taking a single snapshot. For example, thespecialized data agent 440 determines what other data agents 440 arerunning or installed on the client 420. The specialized data agent 440can determine what application data may be stored in the informationstore 430 by determining the other data agents 440 on the client 420.The specialized data agent 440 instructs the other data agents 440 toquiesce associated applications 460. The specialized data agent 440 canquiesce its own associated application 460. The other data agents 440can notify the specialized data agent 440 once their associatedapplications 460 are quiesced. The specialized data agent 440 can thennotify the snapshot manager 450 that the applications 460 are ready fora single snapshot. In certain embodiments, the snapshot manager 450 mayperform some or all of the functions of the specialized data agent 440.

In certain embodiments, an application 460 may request a snapshot forits data. The application 460 can send a request to the snapshot manager450 or the storage manager 410. The request may be in the form of a job,and the snapshot manager 450 may manage the jobs from variousapplications 460 (e.g., in a queue). The request for snapshot of anapplication 460 may be generated and sent by the data agent 440 for theapplication 460. The data agent 440 for the first job received in agiven time period may be designated to be the specialized data agent 440and may instruct the data agents 440 for subsequent jobs to placeassociated applications 440 in consistent states.

At data flow step 3, the data agents 440 notify that applications 460are quiesced. After the data agents 440 instruct the applications 460 toenter consistent states, the applications 460 can notify the data agents440 once they are quiesced. The data agents 440 in turn can notify thesnapshot manager 450 or the storage manager 410 that the applications460 are ready for a snapshot. In some embodiments, the specialized dataagent 440 is notified by the other data agents 440, and the specializeddata agent 440 lets the snapshot manager 450 or the storage manager 410know that the applications 460 are ready for a snapshot. In certainembodiments, not all applications 460 notify that they are ready for asnapshot, but if a sufficient number of applications 460 are inconsistent states, the snapshot manager 450 may proceed with taking thesnapshot. The sufficient number of applications 460 for a snapshot maybe defined by a threshold value that is managed by the snapshot manager450.

At data flow step 4, the snapshot manager 450 takes a snapshot of theinformation store or primary storage 430. As explained above, thesnapshot taken may be of a logical volume. The snapshot manager 450 maynot take the snapshot itself, but arrange for appropriate components inthe system 400 to obtain the snapshot. In one embodiment, theinformation store or primary storage device 430 is capable of takinghardware-based snapshots. The snapshot manager 450 instructs the mediaagent 470 associated with the information store 430 to take a snapshotof a particular volume, and the media agent 470 sends a request to theinformation store 430 to take a hardware snapshot.

In some embodiments, the information store 430 includes data for adatabase application 460. For a database application 460, the databasedata and the database log data may be backed up separately. For example,the database data may be included in the single snapshot for multipleapplications. The database transaction logs may be backed up morefrequently (e.g., every 15 minutes) and may be backed up separatelyfrom, or in addition to, the single snapshot that includes the databasedata. The transaction logs may be backed up by the data agent 440associated with the database application 460. For example, one or morelog files of the transaction log are copied to secondary storage devices480. When a database application 460 data is backed up (e.g., in a fullbackup), the database logs may be truncated. Log truncation may refer tofreeing up space in the logical log for reuse by the log file. Forexample, the transaction log has a certain amount of disk spaceavailable, and log records should be deleted periodically to free upspace. Logs may be truncated when a backup is performed successfully,for example, in order to prevent the log file from overflowing. Incertain embodiments, the backup of the database data is performedthrough the single snapshot, for example, instead of using the dataagent 440 for the corresponding database application 460. In such case,the logs may not be truncated properly. Accordingly, the snapshotmanager 450 can coordinate to truncate the database logs at the time thesingle snapshot is taken. In one embodiment, the snapshot manager 450instructs the data agent 440 associated with the database application460 to truncate the logs. The single snapshot, which includes thedatabase data, and the log backup data can be stored in separate storagedevices and/or different types of media.

In a full backup of a database, generally the inactive part of the logmay not be truncated until all its log records are included or capturedin a log backup so that the log chain can be maintained (e.g., forrecovery). The log chain may refer to a series of log records having anunbroken sequence of log sequence numbers.

In certain embodiments, the transaction log may be a wrap-around file.The transaction log may include one or more physical files. When thedatabase is created, the logical log file begins at the start of thephysical log file, and new log records are added at the end of thelogical log and expand toward the end of the physical log. Each physicallog file may be divided internally into a number of virtual log files.Log truncation can free space in the logical log by deleting inactivevirtual log files from the start of the logical log. Virtual log filesmay define the unit of space that can be reused. For example, virtuallog files that contain only inactive log records are truncated. Theactive portion of the transaction log may not be truncated because theactive portion is used to recover the database. The most recentcheckpoint can define the active portion, and the log can be truncatedup to the checkpoint.

A checkpoint may refer to an identifier or reference that identifies thestate of the database at a point in time. In general, modifications todatabase pages are performed in memory and are not necessarily writtento disk after every update. Therefore, the database system may perform acheckpoint periodically to write these updates that are held in-memoryto the storage disk. Writing these updates to storage disk can create apoint in time to which the database system can apply changes containedin a transaction log during recovery after an unexpected shut down orcrash of the database system. The checkpoint may include informationabout the log sequence number of the first log record that should bepresent for a successful database-wide rollback.

Although log truncation is explained above with reference a databaseapplication 460, log truncation can apply to other types of applications460 that have transaction logs. For example, Exchange also has atransaction log, and Exchange logs can be truncated in a similar manner.

In some embodiments, the single snapshot is taken for a virtual machine(VM), and one of the applications 460 executing or installed on the VMis a database application 460. In such case, a single snapshot is takenof the VM data, which includes the database data, and the logs arebacked up by the data agent 440 for the database application 460 insidethe VM. At the time of restore, the database data can be restored fromthe VM snapshot, and the log data can be restored from the log backup.

At data flow step 5, the media agents 470 store the snapshot in thestorage devices or secondary storage 480. As explained above, thesnapshot can be a snapshot of a volume 435 or a LUN 431 in theinformation store 430. In the example of FIG. 4, the snapshot 485 a ofVolume 1 435 a is stored in the storage device 480. The snapshot 485 aincludes the data for Client 1 420 a, which is stored in Volume 1 435 a.In other embodiments, the snapshot may be of a LUN 431. For example, inFIG. 4, the storage device 480 can store the snapshot 481 a of LUN 1 431a. If Volume 1 435 a is included in LUN 1 431 a, the snapshot 481 a caninclude the data of Volume 1 435 a.

In some embodiments, the snapshot is stored in the same storage deviceas the information store or primary storage device 430. In such case,the information store 430 also serves as the secondary storage device480, and the primary data for applications 460 and the snapshot data forthe applications 460 are stored on the same storage device. Theinformation store 430 may be a storage device that is capable ofperforming a hardware snapshot. The media agents 470 may store anymetadata relating to the snapshot operation or the snapshot in the mediaagent index 475. For example, the metadata can include any metadatagenerated during the snapshot operation.

In certain embodiments, the snapshot is partitioned into multiple partsrelating to the applications 460 for which the snapshot is taken. Forexample, the portion of the snapshot relating to one application 460 maybe partitioned and stored separately, and the portion of the snapshotrelating to another application 460 may be partitioned and storedseparately. The portions of the snapshot that do not relate to anapplication 460 of interest may be pruned or discarded. The portions formultiple applications 460 may be partitioned in turn, and once theportions corresponding to all applications 460 of interest have beenstored as a separate backup copy, the snapshot data may be deleted.

At data flow step 6, the media agents 470 create application mappingdata. Mapping data may also be referred to as “mapping information” or“mapping metadata.” A data agent 440 can have access to informationabout how the data and/or directories of an associated application 460are structured, how the files generated by the application 460 arearranged, etc. Accordingly, the data agent 440 can determine which partof the snapshot belongs to or relates to a particular application 460.In one embodiment, the data agent 440 sends such information to themedia agent 470 so the media agent 470 can generate mapping metadataregarding the location of the data of an application 460 within asnapshot. For example, the media agent 470 can create mapping metadatathat maps data of an application 460 to a particular location(s) in thesecondary storage device 480. The mapping metadata can be stored in themedia agent index 475. The mapping metadata can be referenced whenrestoring data for that application 460. In some embodiments, themapping metadata may be stored as component 225 which is described withrespect to FIGS. 2 and 8-10.

The data agents 440 may gather information and/or metadata for creatingthe mapping data before a snapshot is taken. As explained above, a dataagent 440 may be aware of how the data of its associated application 460is formatted, and the data agent 440 can also have access to informationregarding how the directories of the associated application 460 areorganized or structured. In an illustrative example, SQL Server dataagent 440 knows that SQL Server data is stored under directory “C:\SQL.”SQL Server data agent 440 also knows the subdirectories included in the“C:\SQL” directory. For instance, SQL Server data agent 440 knows thatthe data for Database 1 is stored under “C:\SQL\DB1,” and Database 1logs are stored under “C:\SQL\DB1\logs.” SQL Server data agent 440 mayalso be aware that certain file extensions are associated with SQLServer. Based on this information, SQL Server data agent 440 candetermine which part of the volume includes SQL-related data. SQL Serverdata agent 440 passes on this information to one or more media agents470 so that they can generate the mapping data regarding which portionof the snapshot pertains to SQL Server data. The media agents 470 canrefer to the information from the SQL Server data agent 440. Forexample, a media agent 470 can determine which part of the snapshot datacorresponds to “C:\SQL” in the logical volume in the information store430.

In one embodiment, the data agents 440 reference a file table of thefile system associated with the logical volume for which the snapshot isobtained. Such a file table may be associated with a particularoperating system. For example, the file table can be the master filetable (MFT) used by Windows operating systems (Windows OS). There couldbe one table per volume. The file table can include information aboutthe files in a volume. In some embodiments, the snapshot manager 450 orthe media agents 470, instead of the data agents 440, may refer to thefile table.

Although the data flow step 6 is described after data flow step 5, dataflow steps 5 and 6 may be performed concurrently or in a different order(e.g., data flow step 6 is performed before data flow step 5). After thesnapshot is obtained, the applications 460 can be unquiesced and resumeoperations. The snapshot manager 450 may instruct the respective dataagent 440 to communicate with the associated applications 460 that theyno longer need to be in consistent states. The applications 460 canreturn to normal state and may inform the data agents 440 after they areunquiesced. In turn, the data agents 440 may notify the snapshot manager450 that the respective applications 460 are unquiesced.

By utilizing a single snapshot for multiple applications, the system 400may reduce the number of snapshots taken since a snapshot of a volumecan be taken less frequently. This can reduce the amount of resourcesused for generating and storing snapshots of primary storage devices.For example, a license for a snapshot software may be priced based onthe number of allowed snapshots. Accordingly, taking fewer snapshots toback up data in the primary storage can be economical.

FIG. 5 is a data flow diagram illustrative of the interaction betweenthe various components of another exemplary information managementsystem 500 configured to implement recovery operations from a singlesnapshot for multiple applications, according to certain embodiments. Asillustrated, the exemplary information management system 500 includes astorage manager 510, one or more clients 520, one or more informationstores or primary storage devices 530, one or more data agents 540, oneor more snapshot managers 550, one or more applications 560, one or moremedia agents 570, and one or more secondary storage devices 580. Thesystem 500 and corresponding components of FIG. 5 may be similar to orthe same as the system 100, 200, 400 and similarly named (though notnecessarily numbered) components of FIGS. 1D, 2, and 4.

Moreover, depending on the embodiment, the system 500 of FIG. 5 mayadditionally include any of the other components shown in FIGS. 1D, 2,and 4 that are not specifically shown in FIG. 5. The system 500 mayinclude one or more of each component. All components of the system 500can be in direct communication with each other or communicate indirectlyvia the client 520, the storage manager 510, the media agent 570, or thelike. In certain embodiments, some of the components in FIG. 5 shown asseparate components can reside on a single computing device, or viceversa. For example, the snapshot manager 550 can be on the storagemanager 510, the client 520, or on a separate computing device. Furtherdetails regarding certain aspects of the system 500 are described ingreater detail above with reference to FIG. 4.

At data flow step 1, the client 520 requests restore of data relating toan application 560. For example, the client 520 may send a request torestore data to the storage manager 510. In turn, the storage manager520 may send a request to an appropriate media agent 570. In someembodiments, the storage manager 510 sends the request to the snapshotmanager 550 and the snapshot manager 550 forwards the request to one ormore media agents 570. The request may be for a file generated by theapplication 560. The data of the application 560 can be restored atvarious levels of granularity. For example, an individual Exchange mailitem or a write within SharePoint may be recovered.

At data flow step 2, the media agent 570 locates the snapshot thatincludes the requested application data. As explained above withreference to FIG. 4, the snapshot can be a single snapshot that includesdata of multiple applications. For instance, the snapshot is a snapshotof a logical volume 535 in a primary storage device 530 taken at aparticular point in time. A primary storage device 530 can include oneor more LUNs 531, and each LUN 531 can include one or more volumes 535.In the example of FIG. 5, data for Client 1 520 a is stored in onevolume 535 a (Volume 1) in a LUN 531 a (LUN 1), and data for Client 2520 b is stored in another volume 535 b (Volume 2) in another LUN 531 b(LUN 2). In the example of FIG. 5, the snapshot 585 a is a snapshot ofVolume 1 535 a at a specific point in time. The snapshot 585 a includesthe data for Client 1 520 a, which is stored in Volume 1 535 a. Or thesnapshot may be a snapshot of a LUN 531 that includes the logical volume535. For instance, in the example of FIG. 5, the snapshot 581 a is asnapshot of LUN 1 531 a, and can include the data of Volume 1 535 a. Insome embodiments, a LUN 531 can include multiple volumes 535, or avolume 535 can include multiple LUNs 531. In certain embodiments, avolume 535 may be configured across multiple primary storage devices530. In some embodiments, more than one media agent 570 is involved inlocating the snapshot and restoring the requested application data. Forexample, the single snapshot may be stored across multiple secondarystorage devices 580.

The secondary storage devices 580 can provide multiple snapshots for thesame volume or LUN taken at different times. The requested applicationdata may be for a specific time, and one or more media agents 570 canrestore from the snapshot for that time (or close to that time). Themedia agent 570 can refer to information or metadata in the media agentindex 575 in order to find the snapshot that includes the requesteddata. After locating the snapshot including the requested data, themedia agent 570 can access the mapping data or information indicatingthe portion of the snapshot related to the application 560. The mediaagent 570 can reference the mapping information in order to determinewhich portion(s) of the snapshot include the data of the application560. The mapping information may be organized by application 560 and bysnapshot. Each application 560 can have its own set of mappinginformation, and the mapping information can be provided for eachsnapshot that includes the data of the application 560. The mappinginformation may be stored in the media agent index 575. In someembodiments, the mapping information may be stored in the system tableas described in FIGS. 2 and 8-10. In some embodiments, the snapshotmanager 550 determines which snapshot includes the requested data and/orwhich part of the snapshot pertains to the application 560.

In one embodiment, the mapping information includes a file table (notshown) of the file system associated with the logical volume 535 in thesnapshot. Such file table may be associated with a particular operatingsystem (e.g., MFT for Windows OS). The file table can includeinformation about the files in the volume. The media agent 570 can referto the information about files in the file table to determine what datain the snapshot is related to the requesting application 560. In acertain embodiment, the mapping information may not be generated duringthe snapshot operation, but may be available or generated based on theinformation in the file table at the time of restore.

At data flow step 3, the media agent 570 restores the requestedapplication data. Once the media agent 570 locates the snapshot thatincludes the data of the application 560 and the portion of thatsnapshot relating to the application 560, the media agent 570 canextract the requested data from the portion of the snapshot relating tothe application 560. The mapping information may include details forrecovering the data of the application 560 at various levels ofgranularity. For instance, the mapping information can indicate where aparticular file is located within the portion of the snapshot relatingto the application 560. The media agent 570 can then restore that fileto the primary storage 530. For example, the media agent 570 copies theblocks for the file to the primary storage device 530. The mappinginformation may also provide information on locating individual writesor items associated with the application 560. The requested data may berecovered to the same volume 535 or LUN 531 for which the snapshot wastaken. For example, the restored data overwrites the existing data. Orthe requested data may be recovered to a different volume 535, LUN 531,or primary storage device 530.

In some embodiments, the snapshot includes data for a databaseapplication 560. As explained above regarding FIG. 4, the data of adatabase application 560 and the log of the database application 560 maybe backed up separately. For example, the log backup and the singlesnapshot that includes the database data can be stored in separatestorage devices and/or different types of media. Accordingly, restoringthe data of the database application 560 can involve restoring both thedata of the database application 560 from the single snapshot and thelog data from the log backup. The data of the database application 560can be restored in a similar manner to restoring data of otherapplications 560. The log data may be restored separately and may beprocessed to form the log chain. The log chain may refer to a series oflog records having an unbroken sequence of log sequence numbers.Restored log files may be placed or arranged in a certain sequence toform the log chain. After the data of the database application 460 isrestored and the database log is properly restored, the user can accessand operate on the requested database data.

FIG. 6 is a flow diagram illustrative of one embodiment of a routine 600for creating a single snapshot for multiple applications. The routine600 is described with respect to the system 400 of FIG. 4. However, oneor more of the steps of routine 600 may be implemented by otherinformation management systems, such as those described in greaterdetail above with reference to FIGS. 1D, 2, and 3. The routine 600 canbe implemented by any one, or a combination of, a client, a storagemanager, a data agent, a snapshot manager, a media agent, and the like.Moreover, further details regarding certain aspects of at least some ofsteps of the routine 600 are described in greater detail above withreference to FIG. 4. Although described in relation to snapshotoperations for the purposes of illustration, the process of FIG. 6 canbe compatible with other types of storage operations, such as, forexample, migration, backups, replication operations, archiving, and thelike.

At block 601, the snapshot manager 450 checks the status of variousapplications 460 with corresponding data agents 440. The snapshotmanager 450 can detect the applications 460 executing on the client 420by determining which data agents 440 are executing on the client 420.

At block 602, the data agents 440 quiesce the associated applications460. For example, the data agent 440 may instruct the application 460 toenter a consistent state. The application 460 can notify the data agent440 subsequent to entering a consistent state. The data agent 440 thencan relay that the application 460 is ready for a snapshot to thesnapshot manager 450.

At block 603, the data agents 440 notify the snapshot manager 450 thatthe associated applications 460 are quiesced. Each data agent 440 cansend a notification to the snapshot manager 450 that its relatedapplication 460 is in a consistent state.

At block 604, the snapshot manager 450 obtains a snapshot of the primarystorage 430 storing the data of the applications 460. The snapshotmanager 450 may obtain the snapshot after receiving notifications fromthe data agents 440 that the associated applications 460 are inconsistent states. In some embodiments, the snapshot manager 450 obtainsthe snapshot after receiving notifications from two or more of the dataagents 440, but not all of the data agents 440. In some cases, waitingfor all applications 460 to enter consistent states may not beefficient, and if most (or a threshold number) of the applications 460are in consistent states, the snapshot can be taken. The snapshot may beof a particular logical volume in the primary storage 430. The logicalvolume can include the data generated by the applications 460. Thelogical volume can also include data associated with a file system ofthe client 420.

Each applications 460 may have a frequency for obtaining a snapshot ofdata associated with the application. In some embodiments, the snapshotmanager 450 obtains the snapshot for two or more applications 460 thathave the same frequency for obtaining a snapshot at the same time. Forexample, the snapshot operation for applications 460 having the samesnapshot frequency may be included in one snapshot storage policy.

At block 605, one or more media agents 470 store the snapshot data inthe secondary storage 480. The secondary storage 480 may be the samestorage device as the information store of the primary storage 430. Forexample, the storage device may be a storage array that is capable ofperforming hardware snapshots, and the snapshot data is stored in thesame array as the production or primary data.

At block 606, the snapshot manager 450 creates application mapping data(e.g., mapping metadata). Each data agent 440 may obtain metadatarelating to the location of the data generated by its associatedapplication 460 in the logical volume. The data agent 440 can haveaccess to information relating to the structure of the data generated bythe application 460 and/or location of the data generated by theapplication 460 in the logical volume. The metadata could includeinformation relating to data structure or one or more directories of theapplication 460. The information relating to the structure of the datagenerated by the application 460 can include the format of the data. Theinformation relating to the location of the data generated by theapplication 460 in the primary storage comprises directory structure ofthe application 460. The snapshot manager 450 may generate mappinginformation that maps a particular application 460 to a portion of thesnapshot relating to that application 460. The mapping information maybe created based on the metadata obtained by the respective data agent440.

The routine 600 can include fewer, more, or different blocks than thoseillustrated in FIG. 6 without departing from the spirit and scope of thedescription. Moreover, it will be appreciated by those skilled in theart and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatileand/or non-transitory storage.

FIG. 7 is a flow diagram illustrative of one embodiment of a routine 700for restoring data of an application from a single snapshot for multipleapplications. The routine 700 is described with respect to the system500 of FIG. 5. However, one or more of the steps of routine 700 may beimplemented by other information management systems, such as thosedescribed in greater detail above with reference to FIGS. 1D, 2, 3 and4. The routine 700 can be implemented by any one, or a combination of, aclient, a storage manager, a data agent, a snapshot manager, a mediaagent, and the like. Moreover, further details regarding certain aspectsof at least some of steps of the routine 700 are described in greaterdetail above with reference to FIG. 5. Although described in relation tosnapshot operations for the purposes of illustration, the process ofFIG. 7 can be compatible with other types of storage operations, suchas, for example, migration, backups, replication operations, archiving,and the like.

At block 701, the storage manager 510 receives instructions to restoreapplication data from a single snapshot 585 containing data of multipleapplications 560. The storage manager 510 may instruct the snapshotmanager 550 to begin the restore process. In some embodiments, thesnapshot manager 550 receives the instructions. The data to be restoredmay be a file, a write, a mail item, etc.

At block 702, the snapshot manager 550 locates the portion of thesnapshot relating to the requested application data. The snapshotmanager 550 can locate the snapshot that includes the data to berestored. Since a number of snapshots may exist in the secondary storage580 for a volume, the snapshot manager 550 may determine from whichsnapshot the requested data should be restored. The snapshot manager 550can make the determination by accessing information in the media agentindex 575. After locating the snapshot of interest, the snapshot manager550 can find the portion of the snapshot that relates to the requestingapplication 560. The snapshot manager 550 may refer to mappinginformation that maps data of the application 560 in the snapshot to theapplication 560 in order to find the relevant portion of the snapshot.The mapping information can be generated based on the metadata obtainedby the data agents 540 associated with the applications 560. The dataagents 540 may obtain metadata relating to the data structure or one ormore directories of the associated applications 560. The storage manager510 or the snapshot manager module 550 can instruct one or more mediaagents 570 to restore the relevant portion of the snapshot from thesecondary storage device(s) 580.

In one embodiment, the mapping information can include a file table ofan operating system of the client 520 from the time the snapshot wastaken. The snapshot manager module 550 can access the file table tolocate the portion of the snapshot corresponding to the data of theapplication 560.

At block 703, one or more media agents 570 restore the requestedapplication data. The snapshot data may be stored across multiplestorage devices 580, and a media agent 570 may be designated tocommunicate with a specific storage device 580. In such case, more thanone media agent 570 can be involved in restoring the requested snapshotdata. The requested application 560 data may be restored to the sameprimary storage device 530 that includes the logical volume the snapshotrelates to. For instance, the restored data may overwrite correspondingdata in the logical volume. Or the restored data may be written toanother part of the logical volume, another volume, another LUN, etc. inthe same primary storage device 530. In another example, the restoreddata is written to a primary storage device 530 that is different fromthe primary storage device 530 that includes the logical volume thesnapshot relates to.

The routine 700 can include fewer, more, or different blocks than thoseillustrated in FIG. 7 without departing from the spirit and scope of thedescription. Moreover, it will be appreciated by those skilled in theart and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatileand/or non-transitory storage.

Shared Snapshot Generation

FIG. 8 provides a flowchart illustrating a process 800 for generatingshared snapshots in accordance with one or more embodiments disclosedherein. The process 800 may be implemented by information managementsystems, such as those described in greater detail above with referenceto FIGS. 1D and 2-5. The process 800 can be implemented by any one, or acombination of, a client, a storage manager, a data agent, a snapshotmanager, a media agent, and the like. Moreover, further detailsregarding certain aspects of at least some of steps of the process 800are described in greater detail above with reference to FIGS. 2-5.Although described in relation to snapshot operations for the purposesof illustration, the process 800 can be compatible with other types ofstorage operations, such as, for example, migration, backups,replication operations, archiving, and the like.

The process 800 may include accessing a LUN and detecting the numberand/or type of applications and/or agents that are running on the LUN(block 810). Such information may be used in determining how to share asnapshot taken of the entire LUN, or a portion thereof. Appropriatesoftware may be directed to quiesce the applications.

The process 800 may further include receiving a request to take asnapshot of the LUN from one or more applications (block 820). Forexample, such request may be directed by a snapshot manager module asdescribed above. In accordance with the request, a single snapshot maybe taken at block 840 of the LUN or a portion thereof, wherein theprocess 800 further includes grouping snapshot requests from multipleapplications in order to partition the single snapshot to be sharedamong the requesting applications.

In order to track the locations of the various snapshot partitions, theprocess 800 may include identifying the locations within the snapshot ofthe data associated with the various applications and cataloging suchinformation in mapping information (block 850). With reference to themapping information, the snapshot may be stored in the storage system asseparate snapshots associated with the separate applications/agents(block 860).

Grouping Applications for Single Snapshot Applicability

As described above, generation of shared snapshots can involve groupingsnapshots requested by multiple applications together in a singlesnapshot of the LUN on which the relevant volumes of data aremaintained. FIG. 9 provides a flowchart illustrating a process 900 forgrouping snapshot requests according to one or more embodimentsdisclosed herein. Snapshot requests associated with separateapplications/agents that are grouped together may share a globalsnapshot of an LUN shared by the applications/agents. The process 900may be implemented by information management systems, such as thosedescribed in greater detail above with reference to FIGS. 1D and 2-5.The process 900 can be implemented by any one, or a combination of, aclient, a storage manager, a data agent, a snapshot manager, a mediaagent, and the like. Moreover, further details regarding certain aspectsof at least some of steps of the process 900 are described in greaterdetail above with reference to FIGS. 2-5. Although described in relationto snapshot operations for the purposes of illustration, the process 900can be compatible with other types of storage operations, such as, forexample, migration, backups, replication operations, archiving, and thelike.

In certain embodiments, snapshot requests are grouped based on time ofreceipt. Grouping snapshot requests based on time relative to the timeof creation of the global snapshot may increase the likelihood that aparticular request with be associated with a state of the source dataadequately represented by the global snapshot. For example, if a requestis made too far removed in time from the generation of the globalsnapshot, data changes occurring during the gap in time may beundesirably, or inadequately reflected in the global snapshot.Therefore, blocks 910-950 provide a time-based process for groupingsnapshot requests. As illustrated by FIG. 9, the first snapshot jobreceived in a relevant time window may be designated as the master job.In certain embodiments, the master job is responsible for creating ordirecting the global snapshot. In addition, the master job may determinehow many LUNs are associated with each database and/or how manydatabases are associated with each LUN. As additional job requests arereceived, such jobs are added to the group until the desired time windowhas elapsed, at which point the group membership may become static.

As described above, once the related snapshots have been groupedtogether, a single global snapshot may be performed (block 970). It maybe necessary or desirable to provide notification of that the groupedsnapshot is to be taken in order to allow for snapshot consistencyand/or application quiescing (block 960). Once the global snapshot hasbeen taken, associated application I/O may be resumed and/or unquiesced(block 980). Furthermore, the portions of the global snapshot thatrelate to each of the grouped snapshots may then be identified andcataloged (block 990). The cataloged portions of the general snapshotmay then be stored as separate snapshots for each of the groupedsnapshots (block 995).

In certain embodiments, when the system desires to prune data from thebackups, the system uses the mapping information to quickly identifydata that can be pruned. For example, if the data associated with aparticular application is being pruned, the mapping informationidentifies where the data is located within the snapshot.

At block 970, the snapshot is taken that is associated with each of thegroup members. For example, a single snapshot may be taken per LUN. Incertain embodiments, the master job is responsible to taking thesnapshot and storing data in the mapping information identifying thelocation of the master job within the snapshot. The master job may thenpass the mapping information to the next job for further additions tothe mapping information. In certain embodiments, each job maintains itsown mapping information. For example, a single job may have access tothe mapping information entries associated with other jobs, but may haveno reason or capability to monitor mapping information data associatedwith other jobs.

When a snapshot job has been completed, associated applications/agentprocesses may receive access to the snapshot for the purposes ofverifying the consistency of the snapshot data. In certain embodiments,when a job no longer has a use for the snapshot, the snapshot is notdiscarded, but is maintained until all group members likewise have noneed for the snapshot. At such point, the snapshot may be discarded.

Snapshot Restoration

In certain embodiments, when the system desires to restore data from thebackups, the system uses the mapping information to identify which datato be restored from the global snapshot. Therefore, it may not benecessary to restore the entire snapshot. When an application requestsrestoration of a portion of the snapshot, the remainder of the snapshotmay be reused by other applications to the extent that the dataassociated with the applications is valid.

FIG. 10 provides a flowchart illustrating a process 1000 for groupingsnapshot requests according to one or more embodiments disclosed herein.The process 1000 may be implemented by information management systems,such as those described in greater detail above with reference to FIGS.1D and 2-5. The process 1000 can be implemented by any one, or acombination of, a client, a storage manager, a data agent, a snapshotmanager, a media agent, and the like. Moreover, further detailsregarding certain aspects of at least some of steps of the process 1000are described in greater detail above with reference to FIGS. 2-5.Although described in relation to snapshot operations for the purposesof illustration, the process 1000 can be compatible with other types ofstorage operations, such as, for example, migration, backups,replication operations, archiving, and the like.

The process 1000 includes receiving a restore request from anapplication relating to snapshot data stored in a global snapshot (block1010). The mapping information may be used to identify applicationsassociated with the snapshot (block 1020), as well as locations withinthe snapshot where various applications are stored (block 1030). Thedata associated with the requesting application may then be restoredaccording to the mapping information (block 1040).

Snapshot Readiness Report

Systems that perform snapshot operations for taking snapshots of data inprimary storage may have different configurations and/or settings. Thisis not limited to systems that manage a single snapshot for multipleapplications. For example, the storage array configuration and/or volumemanager configuration can vary significantly from one customer toanother customer. Because configurations can vary, there might not be aneasy way to check if a snapshot operation will be successful in aparticular configuration. Therefore, it would be useful to provide atool that can verify whether a snapshot operation will succeed in acertain configuration and/or system without actually performing thesnapshot operation. In many cases, system administrators may not findout whether a snapshot operation has problems until the snapshotoperation fails at runtime.

As mentioned above, snapshot operations may be implemented and/ormanaged as storage policies. For example, a system administrator candefine a storage policy specifying how frequently a snapshot should betaken of certain volumes and/or storage devices. Often, such snapshotstorage policies may be run at designated times without determining,prior to the designated times, whether the snapshot storage policieswill run successfully or not. Many parameters can be involved insnapshot operations, and if any one of the parameters is not met, asnapshot operation could fail.

Accordingly, an information management system according to certainaspects of the disclosure may check or determine whether snapshotoperations will work prior to executing them. This is not limited tosystems that manage a single snapshot for multiple applications, and mayapply to any snapshot operations that occur in an information managementsystem. The concept of whether the system configuration and/or settingsare appropriate or ready for taking a snapshot and/or whether aparticular snapshot storage policy will work can generally be referredto as “snapshot readiness.” In some cases, the information managementsystem can generate reports relating to the determination. Such reportsmay be referred to as “snapshot readiness reports.”

FIG. 11 is a data flow diagram illustrative of the interaction betweenthe various components of an exemplary information management system1100 configured to implement snapshot readiness determination, accordingto certain embodiments. As illustrated, the exemplary informationmanagement system 1100 includes a storage manager 1110, one or moreclients 1120, one or more information stores or primary storage devices1130, a snapshot readiness manager 1150, one or more media agents 1170,and one or more secondary storage devices 1180. The system 1100 andcorresponding components of FIG. 11 may be similar to or the same as thesystem 100, 200, 400, 500 and similarly named (but not necessarilynumbered) components of FIGS. 1D, 2, 4, and 5.

Moreover, depending on the embodiment, the system 1100 of FIG. 11 mayadditionally include any of the other components shown in FIGS. 1D, 2,4, and 5 that are not specifically shown in FIG. 11 (e.g., data agents,applications, etc.). The system 1100 may include one or more of eachcomponent. All components of the system 1100 can be in directcommunication with each other or communicate indirectly via the client1120, the storage manager 1110, the media agent 1170, or the like. Incertain embodiments, some of the components in FIG. 11 shown as separatecomponents can reside on a single computing device, or vice versa. Forexample, the snapshot readiness manager 1150 can be on the storagemanager 1110, the media agent 1170, or on a separate computing device.

At data flow step 1, a user (e.g., a system administrator) creates asnapshot storage policy. The snapshot storage policy can define variousparameters or criteria for performing a snapshot operation. Examples ofparameters and/or criteria can include: frequency of snapshot, primarystorage device(s) for which a snapshot should be taken, secondarystorage device(s) where the obtained snapshot should be stored,application type, volume, etc. The snapshot storage policies may bestored in and managed by the storage manager 1110.

At data flow step 2, the snapshot readiness manager 1150 determines orchecks whether the system 1100 can successfully execute the snapshotstorage policy. Such determination may be referred to as “snapshotreadiness test.” The snapshot readiness manager 1150 can run a snapshotreadiness test for a storage policy at user request, prior to executionof the storage policy, at a predetermined interval, etc. In someembodiments, the snapshot readiness test may be run at the time ofinstallation at a location.

Some of the items or factors the snapshot readiness manager 1150 checkscan include: availability of primary storage devices 1130 for whichsnapshots should be taken, availability of secondary storage devices1180 where snapshots should be stored, connectivity to the primarystorage devices 1130 and/or secondary storage devices 1180, any licensesfor snapshot software, user credentials for connecting to primarystorage devices 1130 and/or secondary storage devices 1180, etc.

The primary storage devices 1130 may be configured as one or morestorage arrays that each include one or more LUNs 1131. A LUN 1131 mayinclude one or more logical volumes 1135. The system 1100 may use avolume manager software to manage the storage arrays, LUNs, and/orvolumes. A number of volume manager software or applications areavailable, and the system 1100 may use a particular volume manager. Thestorage array configurations and/or the volume manager configurationscan vary for different customers. In some embodiments, the snapshotstorage policy is defined to take a snapshot of a LUN 1131 or a volume1135 within a LUN 1131.

The storage manager 1110 may manage configurations and/or settingsrelating to arrays, which may be referred to as “storage arraymanagement” or “array management.” Some examples of information relatingto an array include: IP address of the array, array ID, username andpassword for connecting to the array, etc. The storage manager 1110 mayhave information relating to which host bus adapter (HBA) cards shouldbe used to connect to a particular storage array. The storage manager1110 can also have information relating to which media agents 1170should be used to connect to a storage array. The storage manager 1110may also have credentials used for connecting to an array. The storagemanager 1110 may have licensing information relating to the snapshotsoftware and/or application used to take snapshots. For instance, thesnapshot software provider may grant a license to take a certain numberof snapshots for a designated amount. In order to take snapshots, thesystem 1100 should have a valid license.

The snapshot readiness manager 1150 may refer to any of the informationmanaged by the storage manager 1110 in order to determine whether thesnapshot storage policy will work. In certain embodiments, the snapshotreadiness manager 1150 is distinguishable from and is responsible fordifferent functionality from the snapshot manager 450 and/or 550discussed above. However, these entities may be implemented in a unifiedmodule in some embodiments; in other embodiments, they may beimplemented in distinct modules that reside on the same or differentcomponents of an information management system, such as the illustrativesystem 200 of FIG. 2 or any of the systems described with respect toFIGS. 1-12. For example, the snapshot readiness manager 1150 can accessinformation regarding which media agent 1170 should be used to connectto the array for storing the snapshot as specified in the storagepolicy. The snapshot readiness manager 1150 can also access array IPaddress, array ID, and credentials to the designated media agent 1170.If the media agent's 1170 connection to the array is successful, thesnapshot readiness manager 1150 can know that the information providedto the media agent 1170 is valid.

One of the factors the snapshot readiness manager 1150 may check iswhether the one or more HBAs that can be used to connect to an array areworking. An HBA may connect a host computer to network and storagedevices. An information management system may have multiple HBAinterfaces, but only some of them might be used in connection withsecondary storage operations, such as snapshot operations. The snapshotreadiness manager 1150 can obtain the HBA-related information and checkwhether the relevant HBAs are online.

The snapshot readiness manager 1150 can also check whether the one ormore media agents 1170 for connecting to an array are online. When asnapshot operation is to be executed, the storage manager 1110 mayinstruct one or more media agents 1170 in communication with the arrayto obtain a snapshot. If primary storage devices 1130 are capable oftaking hardware snapshots, the media agents 1170 can request the devices1130 to take a snapshot. The media agents 1170 may also create metadataregarding the snapshot and store it in, e.g., the index 1175.

Another factor the snapshot readiness manager 1150 can check isavailability of the primary storage device(s) 1130 for which a snapshotshould be taken. The snapshot readiness manager 1150 can testconnectivity to a particular storage device(s) 1130. If the primarystorage device 1130 is an array, the snapshot readiness manager 1150 cancheck whether the array is online. However, even if an array isgenerally available, a particular volume for which a snapshot should betaken might not be available. The snapshot readiness manager 1150 cancheck with the array whether the specific volume is online.

The snapshot readiness manager 1150 may check similar factors forsecondary storage device(s) 1180. The snapshot readiness manager 1150can check availability of the secondary storage device(s) 1180 wheresnapshot data should be stored. The snapshot readiness manager 1150 cantest connectivity to a particular storage device(s) 1180. Similar to theprimary storage devices 1130, the secondary storage device(s) 1180 maybe configured as one or more storage arrays that each include one ormore LUNs 1181. A LUN 1181 may include one or more logical volumes 1185.If the secondary storage device 1180 is an array, the snapshot readinessmanager 1150 can check whether the array is online. However, even if anarray is generally available, a particular volume on which snapshot datashould be stored might not be available. The snapshot readiness manager1150 can check with the array whether the specific volume is online. Thearray can inform the snapshot readiness manager 1150 of the onlinestatus of volumes within the array. The snapshot readiness manager 1150may check whether there is enough space to store the snapshot data in aparticular array and/or volume within the array.

In some embodiments, the same storage devices may be used to store bothprimary data and secondary data as in FIG. 2. For example, in someembodiments a hardware storage array can store both primary andsecondary data. The secondary storage device 1180 may be a storage arraythat is capable of performing hardware-based snapshots. In such cases,the primary data for which the snapshot should be taken resides in thestorage array, and the snapshot of the primary data can also be storedin the storage array. Where the same storage devices are used as bothprimary storage 1130 and secondary storage 1180, the snapshot readinessmanager 1150 may only check once regarding whether the array and/or thevolume is available. The snapshot readiness manager 1150 may check asmany times as appropriate, depending on the number and status of arraycomponents and/or volumes, whether they are available for a snapshotoperation.

The snapshot readiness manager 1150 may also check whether the usercredentials provided for connecting to a certain storage array arevalid. The snapshot readiness manager 1150 may attempt to establish aconnection to the storage array using the credentials. The credentialsmay be included in the array management information. The arraymanagement information may include information regarding various storagearrays and properties.

The snapshot readiness manager 1150 can also check whether the licensefor a particular snapshot application is valid. For example, thesnapshot readiness manager 1150 can determine if a specific media agent1170 for obtaining the snapshot has a license to perform a snapshotoperation. In one embodiment, the media agent 1170 that does not have alicense for a snapshot application is unable to connect to an array thatincludes the volume for which a snapshot should be taken. For example,the array is capable of performing hardware snapshots, and only themedia agents 1170 with the license for the array can connect to thearray and request snapshots. In this embodiment, the snapshot readinessmanager 1170 can determine whether the license for the snapshotapplication is valid or not by establishing a connection to the array.The license information may be included in the array managementinformation.

Some of the factors are listed above as examples of what the snapshotreadiness manager 1150 may check. The snapshot readiness manager 1150can check any other factors as appropriate. By testing variousparameters for a snapshot operation, the snapshot readiness manager 1150can determine whether a certain snapshot storage policy will executesuccessfully without actually running the storage policy. The parametersor factors tested may include some or all of the examples above, and canalso include other items that are not mentioned.

In certain embodiments, the snapshot readiness manager 1150 also checkswhether a certain system configuration is supported by the informationmanagement system 1100. The snapshot readiness manager 1150 may refer toarray management information in the storage manager 1110 to make suchdetermination. The system configuration can include volume managerconfiguration, storage array configuration, etc. As explained above, anumber of volume manager solutions are available, and customers may useany one of the available volume manager solutions. Depending on thevolume manager solution used, the configuration of an informationmanagement system can differ significantly. For instance, threecustomers that have systems that can generate snapshots all have verydifferent volume manager configurations. The snapshot readiness manager1150 may determine whether a volume manager configuration used by aninformation management system is compatible with snapshot operationsand/or snapshot storage policies.

In one example, a customer may set up two LUNs to mirror each otherusing the volume manager, but the snapshot operations may not becompatible with such setup. The snapshot readiness manager 1150 caninform that the information management system 1100 does not support thetwo mirroring LUN setup. In order to the make the snapshot operationswork, the mirroring may be temporarily stopped or broken. The snapshotreadiness manager 1150 can provide such suggestion or recommendation ifthe information management system 1100 does not support a particularconfiguration.

The storage array configuration may also differ from one customer toanother customer, and the snapshot readiness manager 1150 may check if aparticular array configuration is compatible with snapshot operations.The snapshot readiness manager 1150 can also determine whether thestorage manager 1110 and/or the media agents 1170 support suchconfiguration.

The snapshot readiness test can be run according to user requirements.For example, the snapshot readiness test is run at the time ofinstallation of the system 1100 at a site. It can also be run at thetime of setting up a snapshot storage policy. In another example, thereadiness test may be run prior to execution of any snapshot storagepolicy. The space available on the secondary storage devices 1180 mayvary from day to day, and determining if the policy will succeed on aparticular day can be important. The snapshot readiness test can also beperformed on demand, for example, at the request of a user or a systemadministrator.

At data flow step 3, the snapshot readiness manager 1150 creates asnapshot readiness report. The snapshot readiness report can specifywhether the snapshot storage policy will succeed if run. In addition,the report may also identify the issues that should be corrected for thestorage policy to work properly. For example, a LUN 1181 or a volume1185 in a secondary storage device 1180 may not be available to storethe obtained snapshot. Or there might not be connection to the secondarystorage device 1180.

Verifying whether a snapshot storage policy will operate properly priorto actual execution can be beneficial. For example, an organization usessnapshots for backing up its data, and if snapshot operations fail, theentire backup can fail. Snapshot readiness test and/or reports can helpwith spotting issues beforehand and without actually executing thepolicy, and the customer does not have to wait until the policy runs tofind out that there are problems. The snapshot readiness report canprovide information regarding any problems associated with performingthe snapshot storage policy, and proposed solutions and/orrecommendations. Although the snapshot readiness test and/or report havebeen explained in terms of snapshot operations, they may also be appliedto other types of information management operations, such as backup,archiving, migration, etc.

FIG. 12 is a flow diagram illustrative of one embodiment of a routine1200 for determining snapshot readiness. The routine 1200 is describedwith respect to the system 1100 of FIG. 11. However, one or more of thesteps of routine 1200 may be implemented by other information managementsystems, such as those described in greater detail above with referenceto FIGS. 1D-5. The routine 1200 can be implemented by any one, or acombination of, a client, a storage manager, a data agent, a snapshotreadiness manager, a media agent, and the like. Moreover, furtherdetails regarding certain aspects of at least some of steps of theroutine 1200 are described in greater detail above with reference toFIG. 11. Although described in relation to snapshot operations for thepurposes of illustration, the process of FIG. 12 can be compatible withother types of storage operations, such as, for example, migration,backups, replication operations, archiving, and the like. The snapshotreadiness determination may apply to any system that performs snapshotoperations, including systems configured to implement a single snapshotfor multiple applications as described in FIGS. 2-5.

At block 1201, the snapshot readiness manager 1150 accesses a snapshotstorage policy. The snapshot storage policy may be defined by a user, asystem administrator, etc. The storage policy can define criteriaassociated with a snapshot operation to obtain a snapshot of data in theprimary storage 1130. The storage policy can be configured to instructthe storage manager 1110 to initiate the snapshot operation (e.g., whenexecuted).

At block 1202, the snapshot readiness manager 1150 determines whetherthe snapshot storage policy will execute successfully at runtime. Thesnapshot readiness manager 1150 can check various factors. For example,the snapshot readiness manager 1150 checks whether the licenseassociated with the snapshot application used to obtain a snapshot ofthe data in the primary storage 1130 is valid. The snapshot readinessmanager 1150 may also determine whether the secondary storage device(s)1180 are available to store the snapshot. A secondary storage device1180 may include multiple logical volumes 1185, and the snapshot datamay be stored in a specific volume; the snapshot readiness manager 1150can check whether the specific volume is available. The snapshotreadiness manager 1150 can also check if the secondary storage device(s)1180 have sufficient space to store the snapshot. The snapshot readinessmanager 1150 may also determine whether the primary storage device(s)1130 are available to obtain the snapshot. A primary storage device 1130may include multiple logical volumes 1135, and the snapshot may beobtained for a specific volume; the snapshot readiness manager 1150 cancheck whether the specific volume is available for taking a snapshot.

The snapshot readiness manager 1150 may also determine whetherconnectivity exists to the primary storage device(s) 1130 or thesecondary storage device(s) 1180. The snapshot readiness manager 1150could instruct one or more media agents 1170 to establish a connectionto the primary storage 1130 or the secondary storage 1180. The mediaagents 1170 may connect to the designated device by using credentials(e.g., user ID, password, etc.) provided by the snapshot readinessmanager 1150. The device in the primary storage 1130 or the secondarystorage 1180 to connect to can be a storage array. The volumes in thestorage array may be managed by a volume manager software. The snapshotreadiness manager 1150 can also check if a particular configuration ofthe volume manager setup is compatible with the snapshot storage policyor is supported by the system 1100. In one embodiment, the primarystorage devices 1130 and the secondary storage devices may be the samedevices 1180. For example, the system 1100 can use storage arrays thathave hardware snapshot functionality. The snapshot storage policy may beconfigured to obtain hardware-based snapshots. The above factors areprovided as examples, and the snapshot readiness manager 1150 can checkany other relevant factors as appropriate.

At block 1203, the snapshot readiness manager 1150 generates a report onthe result of the determination. The report can identify issues thathave been spotted and may also include solutions or recommendations forresolving these issues. For example, if there is insufficient space inthe volume of the secondary storage device 1180 where the snapshotshould be stored, the system administrator can make sure enough space isprovided prior to the time the storage policy is scheduled to run.

The routine 1200 can include fewer, more, or different blocks than thoseillustrated in FIG. 12 without departing from the spirit and scope ofthe description. Moreover, it will be appreciated by those skilled inthe art and others that some or all of the functions described in thisdisclosure may be embodied in software executed by one or moreprocessors of the disclosed components and mobile communication devices.The software may be persistently stored in any type of non-volatileand/or non-transitory storage.

Terminology

Conditional language, such as, among others, “can,” “could,” “might,” or“may,” unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements and/or steps areincluded or are to be performed in any particular embodiment.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof means any connection or coupling,either direct or indirect, between two or more elements; the coupling orconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, refer tothis application as a whole and not to any particular portions of thisapplication. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or” in reference to alist of two or more items, covers all of the following interpretationsof the word: any one of the items in the list, all of the items in thelist, and any combination of the items in the list. Likewise the term“and/or” in reference to a list of two or more items, covers all of thefollowing interpretations of the word: any one of the items in the list,all of the items in the list, and any combination of the items in thelist.

Depending on the embodiment, certain acts, events, or functions of anyof the algorithms described herein can be performed in a differentsequence, can be added, merged, or left out altogether (e.g., not alldescribed acts or events are necessary for the practice of thealgorithms). Moreover, in certain embodiments, acts or events can beperformed concurrently, e.g., through multi-threaded processing,interrupt processing, or multiple processors or processor cores or onother parallel architectures, rather than sequentially.

Systems and modules described herein may comprise software, firmware,hardware, or any combination(s) of software, firmware, or hardwaresuitable for the purposes described herein. Software and other modulesmay reside on servers, workstations, personal computers, computerizedtablets, PDAs, and other devices suitable for the purposes describedherein. Software and other modules may be accessible via local memory,via a network, via a browser, or via other means suitable for thepurposes described herein. Data structures described herein may comprisecomputer files, variables, programming arrays, programming structures,or any electronic information storage schemes or methods, or anycombinations thereof, suitable for the purposes described herein. Userinterface elements described herein may comprise elements from graphicaluser interfaces, command line interfaces, and other suitable interfaces.

Further, the processing of the various components of the illustratedsystems can be distributed across multiple machines, networks, and othercomputing resources. In addition, two or more components of a system canbe combined into fewer components. Various components of the illustratedsystems can be implemented in one or more virtual machines, rather thanin dedicated computer hardware systems. Likewise, the data repositoriesshown can represent physical and/or logical data storage, including, forexample, storage area networks or other distributed storage systems.Moreover, in some embodiments the connections between the componentsshown represent possible paths of data flow, rather than actualconnections between hardware. While some examples of possibleconnections are shown, any of the subset of the components shown cancommunicate with any other subset of components in variousimplementations.

Embodiments are also described above with reference to flow chartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products. Each block of the flow chart illustrationsand/or block diagrams, and combinations of blocks in the flow chartillustrations and/or block diagrams, may be implemented by computerprogram instructions. Such instructions may be provided to a processorof a general purpose computer, special purpose computer, or otherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, create means forimplementing the acts specified in the flow chart and/or block diagramblock or blocks.

These computer program instructions may also be stored in anon-transitory computer-readable memory that can direct a computer orother programmable data processing apparatus to operate in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the acts specified in the flow chart and/or blockdiagram block or blocks. The computer program instructions may also beloaded onto a computer or other programmable data processing apparatusto cause a series of operations to be performed on the computer or otherprogrammable apparatus to produce a computer implemented process suchthat the instructions which execute on the computer or otherprogrammable apparatus provide steps for implementing the acts specifiedin the flow chart and/or block diagram block or blocks.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of the invention can be modified, ifnecessary, to employ the systems, functions, and concepts of the variousreferences described above to provide yet further implementations of theinvention.

These and other changes can be made to the invention in light of theabove Detailed Description. While the above description describescertain examples of the invention, and describes the best modecontemplated, no matter how detailed the above appears in text, theinvention can be practiced in many ways. Details of the system may varyconsiderably in its specific implementation, while still beingencompassed by the invention disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the invention should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the invention with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the invention to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe invention encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the invention under theclaims.

To reduce the number of claims, certain aspects of the invention arepresented below in certain claim forms, but the applicant contemplatesthe various aspects of the invention in any number of claim forms. Forexample, while only one aspect of the invention is recited as ameans-plus-function claim under 35 U.S.C sec. 112(f) (AIA), otheraspects may likewise be embodied as a means-plus-function claim, or inother forms, such as being embodied in a computer-readable medium. Anyclaims intended to be treated under 35 U.S.C. § 112(f) will begin withthe words “means for”, but use of the term “for” in any other context isnot intended to invoke treatment under 35 U.S.C. § 112(f). Accordingly,the applicant reserves the right to pursue additional claims afterfiling this application, in either this application or in a continuingapplication.

What is claimed is:
 1. An information management system configured togenerate a snapshot of data relating to a plurality of applications, thesystem comprising: a client computing device comprising at least one ofa plurality of data agents, each data agent associated with at least oneof a plurality of applications installed on the client computing device,data generated by the plurality of applications stored in a logicalvolume in a primary storage subsystem; and one or more computing devicescomprising computer hardware, the one or more computing devicesconfigured to: detect the plurality of applications installed on theclient computing device; receive a first snapshot request from a firstapplication in the plurality of applications; receive a second snapshotrequest from a second application in the plurality of applications;check with at least one of the plurality of data agents whether thefirst and second applications are in consistent states; in response toreceiving notifications from the at least one of the plurality of dataagents that the first and second applications are in consistent states,obtain a snapshot of the logical volume to satisfy the first snapshotrequest and the second snapshot request; and generate mappinginformation between the first application and a portion of the snapshotrelating to the first application.
 2. The information management systemof claim 1, wherein the one or more computing devices are furtherconfigured to detect that the first application and the secondapplication transmit snapshot requests at a same frequency.
 3. Theinformation management system of claim 1, wherein the one or morecomputing devices are further configured to detect that snapshot dataassociated with the first application and snapshot data associated withthe second application are retained for a first period of time.
 4. Theinformation management system of claim 1, wherein the one or morecomputing devices are further configured to store the snapshot in asecondary storage subsystem.
 5. The information management system ofclaim 1, wherein the snapshot of the logical volume comprises the datagenerated by the plurality of applications that is stored in the logicalvolume.
 6. The information management system of claim 1, wherein thelogical volume comprises data associated with a file system of theclient computing device.
 7. The information management system of claim1, wherein the logical volume comprises data of a virtual machine. 8.The information management system of claim 1, wherein the snapshot is ahardware snapshot.
 9. The information management system of claim 1,wherein a first data agent of the plurality of data agents is associatedwith a database application, an email application, or a file system. 10.The information management system of claim 1, wherein the one or morecomputing devices are further configured to obtain the snapshot of thelogical volume in response to receiving notifications from two or moreof the plurality of data agents, but not all of the plurality of dataagents.
 11. The information management system of claim 1, wherein afirst data agent in the plurality of data agents is configured to obtainmetadata relating to a data structure or one or more directories of thefirst application, and wherein the one or more computing devices arefurther configured to generate the mapping information based on themetadata relating to the data structure or the one or more directoriesof the first application.
 12. A method of generating a snapshot of datarelating to a plurality of applications, the method comprising:detecting, using one or more computing devices, a plurality ofapplications installed on a client computing device, a plurality of dataagents installed at least in part on the client computing device, eachdata agent associated with at least one of the plurality of applicationsinstalled on the client computing device, data generated by theplurality of applications stored in a logical volume in a primarystorage subsystem; receiving a first snapshot request from a firstapplication in the plurality of applications; receiving a secondsnapshot request from a second application in the plurality ofapplications; sending requests to at least one of the plurality of dataagents to check whether the first and second applications are inconsistent states; in response to receiving notifications from the atleast one of the plurality of data agents that the first and secondapplications are in consistent states, obtaining a snapshot of thelogical volume to satisfy the first snapshot request and the secondsnapshot request; and generating, using the one or more computingdevices, mapping information between the first application and a portionof the snapshot relating to the first application.
 13. The method ofclaim 12, further comprising detecting that the first application andthe second application transmit snapshot requests at a same frequency.14. The method of claim 12, further comprising detecting that snapshotdata associated with the first application and snapshot data associatedwith the second application are retained for a first period of time. 15.The method of claim 12, further comprising storing the snapshot in asecondary storage subsystem.
 16. The method of claim 12, wherein thesnapshot of the logical volume comprises the data generated by theplurality of applications that is stored in the logical volume.
 17. Themethod of claim 12, wherein the logical volume comprises data associatedwith a file system of the client computing device.
 18. The method ofclaim 12, wherein a first data agent of the plurality of data agents isassociated with a database application, an email application, or a filesystem.
 19. The method of claim 12, wherein obtaining a snapshot of thelogical volume further comprises obtaining the snapshot of the logicalvolume in response to receiving notifications from two or more of theplurality of data agents, but not all of the plurality of data agents.20. The method of claim 12, wherein a first data agent in the pluralityof data agents is configured to obtain metadata relating to a datastructure or one or more directories of the first application, andwherein generating mapping information further comprises generatingmapping information based at least in part on the metadata relating tothe data structure or the one or more directories of the firstapplication.